fix never releasing lock

Author: simonbuehler

src/ChannelManagers/LocalChannelManager.php

@@ -451,7 +451,7 @@ public function removeObsoleteConnections(): PromiseInterface
         });
 
         return Helpers::createFulfilledPromise(
-            $this->lock()->release()
+            $this->lock()->forceRelease()
         );
     }