FindTBB.cmake Fix, master branch (2019.01.15.)

Renamed TBB_VERSION to TBB_HEADER_VERSION, so it wouldn't interfere with the "LCG version".

The TBB_VERSION variable must be coming from the text file of the LCG release because we set up the RPM dependency of the projects using that variable. For the version read from the TBB header, we need to use a different name.

This is to fix ATLINFR-2871.

AE Build SUCCESS
Build logfiles are available at Jenkins [AE-MERGE-REQUEST #677]

Waiting for a moment while my local build of Athena progresses to a point where I'll see if this is all that needs fixing...

It seems to have been enough...

merged

mentioned in commit dfd9ef9e