AtlasFieldMapCondAlg: apply LoadMapOnStart only when running HLT

Move the `AtlasFieldMapCondAlg.LoadMapOnStart` setting into HLT-specific
job options. This should only be enabled when running in athenaHLT or in
a partition. Plain athena will not have a valid `EventContext` available
before the first event.

This went unnoticed until gaudi/Gaudi!1347 fixed a bug in the initialization
of the `EventIDRange` class.

HLT/Trigger/TrigControl/TrigServices/python/TriggerUnixStandardSetup.py

@@ -113,7 +113,7 @@ def setupCommonServices(flags):
 
 
 def setupCommonServicesEnd():
-    from AthenaCommon.AppMgr import ServiceMgr as svcMgr    
+    from AthenaCommon.AppMgr import ServiceMgr as svcMgr, athCondSeq
     from AthenaCommon.Logging import logging
     from AthenaCommon.AlgSequence import AlgSequence
 
@@ -168,4 +168,7 @@ def setupCommonServicesEnd():
         svcMgr.IOVDbSvc.CacheRun = 0
         svcMgr.IOVDbSvc.CacheTime = 0
 
+    if hasattr(athCondSeq, 'AtlasFieldMapCondAlg'):
+        athCondSeq.AtlasFieldMapCondAlg.LoadMapOnStart = True
+
     return

MagneticField/MagFieldServices/python/MagFieldServicesConfig.py

@@ -25,8 +25,7 @@ def MagneticFieldSvcCfg(flags, **kwargs):
       "name": "AtlasFieldMapCondAlg",
     }
     if flags.Common.isOnline:
-      # online has the map loaded at start and does not use DCS
-      afmArgs.update( LoadMapOnStart = True )
+      # online does not use DCS
       afmArgs.update( UseMapsFromCOOL = False )
     else:
       # UseMapsFromCOOL is default for standard running

MagneticField/MagFieldServices/python/MagFieldServicesSetup.py

-# Copyright (C) 2002-2021 CERN for the benefit of the ATLAS collaboration
+# Copyright (C) 2002-2022 CERN for the benefit of the ATLAS collaboration
 
 # JobOption fragment to set up the magnetic field services and algorithms 
 # Valerio Ippolito - Harvard University
@@ -26,9 +26,8 @@ def AtlasFieldCacheCondAlg(name="AtlasFieldCacheCondAlg",**kwargs):
 
 def AtlasFieldMapCondAlg(name="AtlasFieldMapCondAlg",**kwargs):
   if athenaCommonFlags.isOnline():
-    # online has the map loaded at start and does not use DCS
+    # online does not use DCS
     kwargs.setdefault( "UseMapsFromCOOL", False )
-    kwargs.setdefault( "LoadMapOnStart", True )
 
   return CfgMgr.MagField__AtlasFieldMapCondAlg(name,**kwargs)