Add check to state_isunknown in stop

Author: cmd-ntrf

batchspawner/batchspawner.py

@@ -416,7 +416,7 @@ async def stop(self, now=False):
             return
         for i in range(10):
             await self.poll()
-            if not self.state_isrunning():
+            if not self.state_isrunning() and not self.state_isunknown():
                 return
             await gen.sleep(1.0)
         if self.job_id: