dbms: external dictionaries: fix null pointer dereference after calling unique_ptr::release()

dbms/src/Interpreters/ExternalDictionaries.cpp

@@ -81,6 +81,10 @@ void ExternalDictionaries::reloadImpl(const bool throw_on_error)
 			{
 				const std::lock_guard<std::mutex> lock{dictionaries_mutex};
 
+				const auto & lifetime = dict_ptr->getLifetime();
+				std::uniform_int_distribution<std::uint64_t> distribution{lifetime.min_sec, lifetime.max_sec};
+				update_times[name] = std::chrono::system_clock::now() + std::chrono::seconds{distribution(rnd_engine)};
+
 				const auto dict_it = dictionaries.find(name);
 				if (dict_it->second.dict)
 					dict_it->second.dict->set(dict_ptr.release());
@@ -90,10 +94,6 @@ void ExternalDictionaries::reloadImpl(const bool throw_on_error)
 				/// erase stored exception on success
 				dict_it->second.exception = std::exception_ptr{};
 
-				const auto & lifetime = dict_ptr->getLifetime();
-				std::uniform_int_distribution<std::uint64_t> distribution{lifetime.min_sec, lifetime.max_sec};
-				update_times[name] = std::chrono::system_clock::now() + std::chrono::seconds{distribution(rnd_engine)};
-
 				recreated_failed_dictionaries.push_back(name);
 			}
 		}