REVERT: Revert unecessary changes

include/caosdb/entity.h

@@ -142,7 +142,7 @@ public:
       throw std::out_of_range("Container has size " + std::to_string(size()));
     }
     if (cache.count(index) == 0) {
-      cache.emplace(std::move(index), std::move(T(this->wrapped->Mutable(index))));
+      cache.emplace(index, T(this->wrapped->Mutable(index)));
     }
     return &(cache.at(index));
   }