release/21.2.50.0

Emmanuel Le Guirriec

@guirriec

6e800437 · Merge branch 'cherry-pick-f09c6fd4 [formerly 4f570ad4f4]-21.2' into '21.2' · Dec 10, 2018

21.2 AthDerivation built from 2018-12-10T1031 for EGamma