Remove duplicate eventbus (#250)

I'm fairly certain this was a bad merge as it was introduced
without commentary in c55cde7 which had other bad merges
in the same commit.

Author: benclifford

modules/system/eventbus.py

@@ -104,4 +104,3 @@ async def run(self):
 
 
 eventbus = _EventBus()
-eventbus = _EventBus()