TrigT1CaloCondSvc: Avoid AttributeList copies.

Copying an AttributeList is not thread-safe.
Avoid it.

Trigger/TrigT1/TrigT1CaloCondSvc/TrigT1CaloCondSvc/L1CaloCondSvc.icc

 // -*- C++ -*-
 
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef TRIGT1CALOCONDSVC_L1CALOCONDSVC_ICC
@@ -24,7 +24,7 @@ StatusCode L1CaloCondSvc::store(const T*& pobj, const std::string& key, const st
   ATH_MSG_VERBOSE( "*** L1CaloCondSvc::store() ***" );
   ATH_MSG_VERBOSE(key <<" "<< folder <<" "<< tag );
 
-  // create persitent object (either AthenaAttributeList or CondAttrListCollection) from the transient one
+  // create persistent object (either AthenaAttributeList or CondAttrListCollection) from the transient one
   // the new object is not registered in the TDS
   ATH_MSG_VERBOSE( "*** pobj->makePersistent() ***" );
   DataObject* newConditions = pobj->makePersistent();
@@ -72,7 +72,7 @@ StatusCode L1CaloCondSvc::store(const T*& pobj, const std::string& key, const st
         CondAttrListCollection::const_iterator it_attrList = attrListCollection->begin();
         for(;it_attrList!=attrListCollection->end();++it_attrList) {
           CondAttrListCollection::ChanNum channelNumber = it_attrList->first;
-          CondAttrListCollection::AttributeList attrList = it_attrList->second;
+          const CondAttrListCollection::AttributeList& attrList = it_attrList->second;
 
           newAttrListCollection->add(channelNumber, attrList);
           newAttrListCollection->add(channelNumber, range);
@@ -104,14 +104,15 @@ StatusCode L1CaloCondSvc::store(const T*& pobj, const std::string& key, const st
         CondAttrListCollection::const_iterator it_attrList = attrListCollection->begin();
         for(;it_attrList!=attrListCollection->end();++it_attrList) {
           CondAttrListCollection::ChanNum channelNumber = it_attrList->first;
-          CondAttrListCollection::AttributeList attrList = it_attrList->second;
+          const CondAttrListCollection::AttributeList& attrList = it_attrList->second;
 
           CondAttrListCollection::const_iterator it_coolAttrList = pConstCOOLCondAttrListCollection->chanAttrListPair(channelNumber);
           if(it_coolAttrList!=pConstCOOLCondAttrListCollection->end()) {
             // a corresponding channel is already defined in the COOL folder
             // the new attributes are merged with the old ones
             //CondAttrListCollection::AttributeList* coolAttrList = new CondAttrListCollection::AttributeList(it_coolAttrList->second);
-            CondAttrListCollection::AttributeList coolAttrList(it_coolAttrList->second);
+            CondAttrListCollection::AttributeList coolAttrList;
+            coolAttrList.merge(it_coolAttrList->second);
             coolAttrList.merge(attrList);
 
             mergedAttrListCollection->add(channelNumber, coolAttrList);