Fixes required for mac compilation

As indicated here: https://alice-talk.web.cern.ch/t/o2-dpg-evtgen/1202

Author: ppoava

o2sim.sh

@@ -4,6 +4,7 @@ requires:
   - O2Physics
   - O2DPG
   - QualityControl
+  - EVTGEN
   - AEGIS
   - AliGenO2:(?!osx)
   - jq

photos.sh

@@ -1,7 +1,7 @@
 package: PHOTOS
 version: "%(tag_basename)s"
-tag: "v3.64"
-source: https://github.com/alisw/photospp.git
+tag: "macosx"
+source: https://github.com/Elros60/photospp.git
 requires:
   - HepMC
   - HepMC3