AthenaCommon: ROOT initiailization fix

Make sure that ROOT batch mode gets set properly.

This merge request affects 1 package:

• Control/AthenaCommon

This merge request affects 1 file:

• Control/AthenaCommon/share/Preparation.py

Adding @fwinkl ,@gemmeren ,@maszyman ,@ssnyder as watchers

added Core analysis-review-required main review-pending-level-1 labels

CI Result SUCCESS (hash 9aecfd44)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output (remote access info)

removed review-pending-level-1 label

added review-approved label

added analysis-review-approved label and removed analysis-review-required label

merged

mentioned in commit 11bfd394