factor out connection reset code

nominatim/db/async_connection.py

@@ -33,7 +33,7 @@ class DeadlockHandler:
         self.ignore_sql_errors = ignore_sql_errors
 
     def __enter__(self):
-        pass
+        return self
 
     def __exit__(self, exc_type, exc_value, traceback):
         if __has_psycopg2_errors__:
@@ -190,10 +190,7 @@ class WorkerPool:
                     yield thread
 
             if command_stat > self.REOPEN_CONNECTIONS_AFTER:
-                for thread in self.threads:
-                    while not thread.is_done():
-                        thread.wait()
-                    thread.connect()
+                self._reconnect_threads()
                 ready = self.threads
                 command_stat = 0
             else:
@@ -202,6 +199,13 @@ class WorkerPool:
                 self.wait_time += time.time() - tstart
 
 
+    def _reconnect_threads(self):
+        for thread in self.threads:
+            while not thread.is_done():
+                thread.wait()
+            thread.connect()
+
+
     def __enter__(self):
         return self