Disable using invoke dynamic in Groovy

This is a library and should be compatible also with projects which
do not use indy. In addition indy support in Gradle projects is
currently broken in Idea 14 EAP:
http://youtrack.jetbrains.com/issue/IDEA-126878
Merge pull request #1 from szpak/topic/disableIndy

Disable using invoke dynamic in Groovy