Fix typo in sTGC_SDO in MuonPRD_MultiTruthMaker

Hi,

this MR fixes a typo in MuonPRD_MultiTruthMaker: sTGC_SDO is spelled with a lower-case s, otherwise the STGC_SDO_Container cannot be found. Also the MR makes an adaption in MuonLayerHoughTool to cope with the different scenarios (MM+STGC present, no CSCs) or (MM+STGC and CSCs). With these changes, Run3 reconstruction can be run without a crash in MuonLayerHoughAlg.

Best, Nico