GlobalTag.py: remove misleading print out

Do not print the global tag after expanding it.
This was both misleading (users overriding the global tag would still see the wrong print out) and not in line with the CMSSW practices (messages should be printed via the MessageLogger, not directly to the standard output).
include mixing scenarios for dvmc exercises E8TeV_2012_run198588_BX_50ns 8TeV_2012_run203002_BX_50ns E8TeV_2012_run209148_BX_25ns E8TeV_2012_ZmumugSkim
710TemplateFor71X
Merge pull request #4338 from franzoni/GF_puscenarios_from-CMSSW_7_1_X_2014-06-22-1400

mixing scenarios for dvmc exercise
Merge pull request #4336 from fwyzard/GlobalTag_remove_printout

GlobalTag.py: remove misleading print out
Merged refs/pull/4344/head from repository cms-sw
Merged refs/pull/4341/head from repository cms-sw
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