GMR-149: Revert "allow overrides of LCG_externals_*.txt"
apply Gaudi Merge Request 149: gaudi/Gaudi!149 (merged)
This reverts commit 8f9a292e.
Conflicts:
cmake/UseHEPTools.cmake
see GAUDI-1048
apply Gaudi Merge Request 149: gaudi/Gaudi!149 (merged)
This reverts commit 8f9a292e.
Conflicts:
cmake/UseHEPTools.cmake
see GAUDI-1048