LCGConfig: Call lcg_setup_release only once

Avoid calling lcg_setup_release if the LCG release has already been found successfully before. This saves about 1 second in configuration time (~15% for a single packet WorkDir).

I know, absolutely this is not a big saving but if we manage to find another seven of those, our cmake configuration is going to be "instant" for small WorkDirs ;-)

AE Build SUCCESS
Build logfiles are available at Jenkins [AE-MERGE-REQUEST #618]

Did you try this change with setting up the build of let's say AthenaExternals? I'm just a bit worried whether the "normal" execution path was affected by this or not. (The CI is not completely reliable in this, as in an incremental build the cache variable would already be set just fine. So it doesn't necessarily tell us whether a "clean" build would work fine or not.)

I just double-checked once more. Yes, works fine even from an empty build area.

merged

mentioned in commit a413c90e

mentioned in commit b1e0cb04

mentioned in merge request !395 (merged)