Rails3 log format - fixes syntax error while parsing parameter line with file upload

```
/usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/request.rb:40:in `eval': (eval):1: syntax error, unexpected tCONSTANT, expecting '}' (SyntaxError)
...90 @original_filename="IMG_2228.JPG", @content_type="image/j...
...                               ^
(eval):1: syntax error, unexpected tIDENTIFIER, expecting end-of-input
...2228.JPG", @content_type="image/jpeg", @headers="Content-Dis...
...                               ^
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/request.rb:40:in `convert_eval'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/request.rb:20:in `convert_value'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/line_definition.rb:122:in `block in convert_captured_values'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/line_definition.rb:119:in `each'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/line_definition.rb:119:in `each_with_index'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/line_definition.rb:119:in `convert_captured_values'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/request.rb:114:in `add_parsed_line'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/request.rb:145:in `<<'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:315:in `update_current_request'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:230:in `parse_line'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:187:in `parse_io_19'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:134:in `block in parse_file'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:134:in `open'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:134:in `parse_file'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:95:in `block in parse_files'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:95:in `each'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:95:in `parse_files'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/source/log_parser.rb:81:in `each_request'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/lib/request_log_analyzer/controller.rb:339:in `run!'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/gems/request-log-analyzer-1.13.1/bin/request-log-analyzer:133:in `<top (required)>'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/bin/request-log-analyzer:23:in `load'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/bin/request-log-analyzer:23:in `<main>'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/bin/ruby_executable_hooks:15:in `eval'
	from /usr/local/rvm/gems/ruby-2.1.3@request-log-analyzer/bin/ruby_executable_hooks:15:in `<main>'
```