Avoid loading emacs temp files from config path

Emacs can create temporary files in the config path and logstash will load them with duplicate directives. This can result in cryptic failures such as

{:message=>"syslog tcp listener died", :address=>"0.0.0.0:5544", :exception=>#<Errno::EADDRINUSE: Address already in use - bind - Address already in use>, :backtrace=>["org/jruby/ext/socket/RubyTCPServer.java:118:in `initialize'", "org/jruby/RubyIO.java:876:in `new'", "file:/usr/local/bin/logstash-1.1.5-monolithic.jar!/logstash/inputs/syslog.rb:139:in `tcp_listener'", "file:/usr/local/bin/logstash-1.1.5-monolithic.jar!/logstash/inputs/syslog.rb:94:in `run'"], :level=>:warn}