TauAnalysisTools: do not compile TauOverlappingElectronLLHDecorator in AnalysisBase

TauOverlappingElectronLLHDecorator depends on an EGamma tool which is not avaible in AnalysisBase. To make TauAnalysisTools compiel, this class is ignored in AnalysisBase. In the future, we may not need this class at all.

PhysicsAnalysis/TauID/TauAnalysisTools/Root/TauOverlappingElectronLLHDecorator.cxx

+#ifndef XAOD_STANDALONE
+
 /*
   Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
 */
@@ -211,3 +213,5 @@ StatusCode TauOverlappingElectronLLHDecorator::beginEvent()
 }
 
 //______________________________________________________________________________
+
+#endif