TauAnalysisTools: Fix placement of using directive.

Using directives should come after all #includes.

PhysicsAnalysis/TauID/TauAnalysisTools/test/ut_TauAnalysisTools_test.cxx

 /*
-  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef TAUANALYSISTOOLS_UT_TAUANALYSISTOOLS_TEST_H
@@ -11,7 +11,6 @@
 #include "GaudiKernel/ToolHandle.h" //for better working with tools
 
 #include "AsgMessaging/MessageCheck.h" //messaging
-using namespace asg::msgUserCode;  //messaging
 
 //ROOT includes
 #include "TString.h"
@@ -28,6 +27,8 @@ using namespace asg::msgUserCode;  //messaging
 // EDM include(s):
 #include "xAODTau/TauJetContainer.h"
 
+using namespace asg::msgUserCode;  //messaging
+
 int main( int argc, char* argv[] )
 {
   ANA_CHECK_SET_TYPE (int);