Drop magnetic field callback in TRT_DetElementsRoadMaker_xk (ATLASRECTS-4727)

Drop magnetic field callback in TRT_DetElementsRoadMaker_xk. Still magnetic field around origin is retrieved.

https://its.cern.ch/jira/browse/ATLASRECTS-4727

The changes are almost the same as !20629 (merged)

RunTier0Tests.py was fine. RunTier0Tests.log

At lxplus057.cern.ch, with Athena master 2019-01-29T2139 x86_64-centos7-gcc8-opt, I ran

Reco_tf.py --digiSteeringConf 'StandardSignalOnlyTruth' --conditionsTag 'default:OFLCOND-MC16-SDR-25' --valid 'True' --pileupFinalBunch '6' --numberOfHighPtMinBias '0.2595392' --autoConfiguration 'everything' --numberOfLowPtMinBias '99.2404608' \
    --preInclude 'HITtoRDO:Digitization/ForceUseOfPileUpTools.py,SimulationJobOptions/preInlcude.PileUpBunchTrainsMC16c_2017_Config1.py,RunDependentSimData/configLumi_run310000.py' --postExec 'all:CfgMgr.MessageSvc().setError+=["HepMcParticleLink"]' "ESDtoAOD:fixedAttrib=[s if 'CONTAINER_SPLITLEVEL = \'99\'' not in s else '' for s in svcMgr.AthenaPoolCnvSvc.PoolAttributes];svcMgr.AthenaPoolCnvSvc.PoolAttributes=fixedAttrib" --postInclude 'default:PyJobTransforms/UseFrontier.py' --preExec 'all:rec.Commissioning.set_Value_and_Lock(True);from AthenaCommon.BeamFlags import jobproperties;jobproperties.Beam.numberOfCollisions.set_Value_and_Lock(20.0);from LArROD.LArRODFlags import larRODFlags;larRODFlags.NumberOfCollisions.set_Value_and_Lock(20);larRODFlags.nSamples.set_Value_and_Lock(4);larRODFlags.doOFCPileupOptimization.set_Value_and_Lock(True);larRODFlags.firstSample.set_Value_and_Lock(0);larRODFlags.useHighestGainAutoCorr.set_Value_and_Lock(True); from LArDigitization.LArDigitizationFlags import jobproperties;jobproperties.LArDigitizationFlags.useEmecIwHighGain.set_Value_and_Lock(False)' 'ESDtoAOD:from TriggerJobOpts.TriggerFlags import TriggerFlags;TriggerFlags.AODEDMSet.set_Value_and_Lock("AODSLIM");' \
    --geometryVersion 'default:ATLAS-R2-2016-01-00-01' --numberOfCavernBkg '0'  --inputLowPtMinbiasHitsFile mc16_13TeV/HITS.10701323._007457.pool.root.1 --inputHighPtMinbiasHitsFile mc16_13TeV/HITS.10701335._002690.pool.root.1 --inputHITSFile mc16_13TeV/HITS.12458448._055308.pool.root.1 --outputESDFile ESD.pool.root --maxEvents 100 --digiSeedOffset1 1 --digiSeedOffset2 1 --jobNumber 1 \
    --steering 'doRDO_TRIG'

• In RAWtoESD, 32050.909 ms took for one event, 1.15759793 ms was increased. This corresponds to 4*10^-5.
• In RDOtoRDOTrigger, 5890.202 ms took for one event, 0.04692740 ms was increased. This corresponds to 8*10^-6.