Simplify trigger events (now guaranteeed to receive list of events)

Don't bother checking if list empty - this function is not called often

sanic/server.py

@@ -256,9 +256,6 @@ def trigger_events(events, loop):
     :param events: one or more sync or async functions to execute
     :param loop: event loop
     """
-    if events:
-        if not isinstance(events, list):
-            events = [events]
     for event in events:
         result = event(loop)
         if isawaitable(result):