tests: set dbus request to the right path

Signed-off-by: Yuxuan Shui <[email protected]>

Author: yshui

tests/testcases/issue299.py

@@ -21,7 +21,7 @@
 
 async def get_client_win_async(wid):
     message = await bus.call(Message(destination='com.github.chjj.compton.'+display,
-        path='/',
+        path='/com/github/chjj/compton',
         interface='com.github.chjj.compton',
         member='win_get',
         signature='us',