[ATLASRECTS-6153] Add SG check protection to avoid warnings on R2 AOD
Minor fix as per description.
Avoids
InputMetaDataStore 0 WARNING retrieve(const): No valid proxy for object TriggerMenuJson_HLT of type xAOD::TriggerMenuJsonContainer(CLID 1221262614)
InputMetaDataStore 0 WARNING retrieve(const): No valid proxy for object TriggerMenuJson_L1 of type xAOD::TriggerMenuJsonContainer(CLID 1221262614)
InputMetaDataStore 0 WARNING retrieve(const): No valid proxy for object TriggerMenuJson_HLTPS of type xAOD::TriggerMenuJsonContainer(CLID 1221262614)
InputMetaDataStore 0 WARNING retrieve(const): No valid proxy for object TriggerMenuJson_L1PS of type xAOD::TriggerMenuJsonContainer(CLID 1221262614)
on R2 input