Analytics: fix to unit cache management

analytics/includes/OperatorTemplate.h

@@ -397,8 +397,9 @@ public:
         }
 
         if(_unitCache->size() >= _unitCacheLimit) {
-            U_Ptr oldest = _insertionLUT->begin()->second;
-            _unitCache->erase(oldest->getName());
+            auto oldest = _insertionLUT->begin();
+            _unitCache->erase(oldest->second->getName());
+            _insertionLUT->erase(oldest->first);
         }
         _unitCache->insert(make_pair(unit->getName(), unit));
         // The template unit must never be deleted, even if the cache is full; therefore, we omit its entry from