Bug fixes for using logback.

Hi -

I ran into some issues with using the `logback` system.  First, the indentation issue referenced in #2, and then a TypeError (see below).  These couple of changes resolved my issues, so far anyway.

```
TypeError: can't convert false into String
|                   expand_path at org/jruby/RubyFile.java:720
|           set_config_property at /Users/matt/code/soomo-analytics-collector/vendor/bundle/jruby/1.9/gems/trinidad_logging_extension-1.0.0/lib/trinidad_logging_extension.rb:44
|                     configure at /Users/matt/code/soomo-analytics-collector/vendor/bundle/jruby/1.9/gems/trinidad_logging_extension-1.0.0/lib/trinidad_logging_extension.rb:25
```