Revert "update developer version to gradle 2.0 RC2"

This reverts commit 316a706eea587243d1dac7eb31fc336e664b048f.
solr 4.9.0

Closes #30565.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
Merge remote-tracking branch 'upstream/master'
update developer version to gradle 2.0 RC2