Fix for TPC distortion treatment (AliceO2Group#2007)

A bug for TPC distortion treatment crept in with the refactor of
AliceO2Group#1966

This commit fixes it.

Author: sawenzel

MC/run/ANCHOR/anchorMC.sh

@@ -126,6 +126,7 @@ echo_info "Substituting ALIEN_JDL_LPMPRODUCTIONTAG=$ALIEN_JDL_LPMPRODUCTIONTAG w
 ALIEN_JDL_LPMPRODUCTIONTAG=$ALIEN_JDL_LPMANCHORPRODUCTION
 
 if [[ $ALIEN_JDL_ANCHOR_SIM_OPTIONS == *"--tpc-distortion-type 2"* ]]; then
+  export O2DPG_ENABLE_TPC_DISTORTIONS=ON
   # set the SCALING SOURCE to CTP for MC unless explicitely given from outside
   export ALIEN_JDL_TPCSCALINGSOURCE=${ALIEN_JDL_TPCSCALINGSOURCE:-"CTP"}
 fi