Fix wrong exceptions in transports

The `setPriority` method have to throw a PriorityNotSupportedException
if the feature is not supported.

Author: FrankGiesecke

GearmanProducer.php

@@ -7,6 +7,7 @@
 use Interop\Queue\Destination;
 use Interop\Queue\Exception\InvalidDestinationException;
 use Interop\Queue\Exception\InvalidMessageException;
+use Interop\Queue\Exception\PriorityNotSupportedException;
 use Interop\Queue\Message;
 use Interop\Queue\Producer;
 
@@ -59,7 +60,7 @@ public function setPriority(int $priority = null): Producer
             return $this;
         }
 
-        throw new \LogicException('Not implemented');
+        throw PriorityNotSupportedException::providerDoestNotSupportIt();
     }
 
     public function getPriority(): ?int