tests/test_py3: fix deprecated loop arg

The loop arg has been removed in python 3.10. The same event loop will
be used without passing the argument, so it can be removed.

Fix for:
  TypeError: gather() got an unexpected keyword argument 'loop'

Related: https://stackoverflow.com/a/60315290
Related: https://docs.python.org/3/library/asyncio-task.html#asyncio.gather
Change-Id: I776bc463246e7a1a9adbb7c06012353d65694507
---
M tests/test_py3.py
1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/tests/test_py3.py b/tests/test_py3.py
index 0d526a9..710dcb8 100644
--- a/tests/test_py3.py
+++ b/tests/test_py3.py
@@ -46,7 +46,7 @@
     print('Serving on {}...'.format(server.sockets[0].getsockname()))
 
     # Async client running in the subprocess plugged to the same event loop
-    loop.run_until_complete(asyncio.gather(asyncio.create_subprocess_exec('./scripts/osmo_ctrl.py', '-g', 'mnc', '-d', test_host, '-p', test_port), loop = loop))
+    loop.run_until_complete(asyncio.gather(asyncio.create_subprocess_exec('./scripts/osmo_ctrl.py', '-g', 'mnc', '-d', test_host, '-p', test_port)))
 
     loop.run_forever()
 

