Migrate RecTransformTests reconstruction tests to threaded setups

Until now all these reconstruction tests ran in serial mode. Now they run with one thread and also run an additional test in parallel (same config) with five threads. The tests specific to physics validation still run in serial mode - my understanding is we won't run physics validation NTUP_PHYSVAL production in MT mode (is that correct @jferrand ,@miochoa ?)

Reconstruction/RecExample/RecJobTransformTests/test/test_amitag_q122.sh

@@ -10,7 +10,7 @@
 # art-include: 21.9/Athena
 
 
-Reco_tf.py --AMI=q122 --DataRunNumber 00191920 --outputESDFile=myESD.pool.root --outputAODFile=myAOD.pool.root --inputBSFile=/cvmfs/atlas-nightlies.cern.ch/repo/data/data-art/RecJobTransformTests/data11_7TeV.00191920.physics_JetTauEtmiss.merge.RAW._lb0257._SFO-9._0001.1.10evts
+Reco_tf.py --athenaopts="--threads=1" --AMI=q122 --DataRunNumber 00191920 --outputESDFile=myESD.pool.root --outputAODFile=myAOD.pool.root --inputBSFile=/cvmfs/atlas-nightlies.cern.ch/repo/data/data-art/RecJobTransformTests/data11_7TeV.00191920.physics_JetTauEtmiss.merge.RAW._lb0257._SFO-9._0001.1.10evts
 
 RES=$?
 echo "art-result: $RES Reco"