Set daemon status on keepalive thread

Author: DavidStirling

src/omero/util/__init__.py

@@ -674,7 +674,7 @@ def run(self):
 
                 ctx.logger.info("Halted")
 
-        self.thread = Task()
+        self.thread = Task(daemon=True)
         self.thread.ctx = self
         self.thread.start()