server: handle event exceptions

Don't allow exceptions to propagate beyond a call to
_process_event().  Make sure the future is not marked
as done prior to setting the result.

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

moonraker/moonraker.py

@@ -293,12 +293,16 @@ class Server:
                              ) -> None:
         events = self.events.get(event, [])
         coroutines: List[Coroutine] = []
+        try:
             for func in events:
                 ret = func(*args)
                 if ret is not None:
                     coroutines.append(ret)
             if coroutines:
                 await asyncio.gather(*coroutines)
+        except ServerError as e:
+            logging.exception(f"Error Processing Event: {fut}")
+        if not fut.done():
             fut.set_result(None)
 
     def register_remote_method(self,