using deprecated config access

[chrisbitmead]

on ShiroGrailsPlugin.groovy line 199 it accesses configuration using the deprecated direct access

grailsApplication.config.info.app.name

instead of:

grailsApplication.config.getProperty('info.app.name')

I think it was very dumb for grails to deprecate this, but it is what it is.

[pmcneil]

This method has some checks for existence and the ability to provide a default I believe, so it's a good thing. Reminds me I need to update this plugin and release it !

[chrisbitmead]

The groovy language also has syntax to check for existence and provide a default.