Tiny refactor (#1058)

Author: robsdedude

src/neo4j/_async/io/_pool.py

@@ -962,5 +962,5 @@ async def on_write_failure(self, address, database):
         async with self.refresh_lock:
             table = self.routing_tables.get(database)
             if table is not None:
-                self.routing_tables[database].writers.discard(address)
+                table.writers.discard(address)
         log.debug("[#0000]  _: <POOL> table=%r", self.routing_tables)

src/neo4j/_sync/io/_pool.py

@@ -959,5 +959,5 @@ def on_write_failure(self, address, database):
         with self.refresh_lock:
             table = self.routing_tables.get(database)
             if table is not None:
-                self.routing_tables[database].writers.discard(address)
+                table.writers.discard(address)
         log.debug("[#0000]  _: <POOL> table=%r", self.routing_tables)