removing redundant `packageApp()` call in bootstrap target shaves ~1sec off many grails commands for me

bootstrap_diff

Not sure if this causes issues elsewhere, but `test-app`, `run-app`, and `package` seem fine. The `packageApp()` method is called again in `loadApp()` so this one seems redundant.

Shaves off about a second for me on a larger app as it removes a redundant call.  YMMV, put it back if you see any issues:

    diff --git a/scripts/_GrailsBootstrap.groovy b/scripts/_GrailsBootstrap.groovy
    index 4c44aa3..218a41a 100644
    --- a/scripts/_GrailsBootstrap.groovy
    +++ b/scripts/_GrailsBootstrap.groovy
    @@ -126,7 +126,7 @@ target(monitorApp:"Monitors an application for changes using the PluginMana
     }
 
     target(bootstrap: "Loads and configures a Grails instance") {
    -    packageApp()
    +    //packageApp()
         loadApp()
         configureApp()
     }

Seems to be a lot of redundant and messy calls in the current gant scripts, I'm really looking forward to the gradle build system that's on the roadmap for grails 3.0.