online_build_set,online_application_set: add Geometry/GEMGeometry

Add Geometry/GEMGeometry to ONLINE build set. It's a new dependency
introduced by Geometry/GlobalTrackingGeometryBuilder.

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
Merge pull request #95 from davidlt/IB/CMSSW_6_2_X/stable

[IB/CMSSW_6_2_X/stable] online_build_set,online_application_set: add Geometry/GEMGeometry