Prevent crash when iterating get_clientlist

[jeth318]

I have noticed that the app crashes intermittently when iterating over clnts['get_clientlist']. It seems like it's undefined sometimes.

I've made a fix for this that I can push in a feature-branch if you want.

Best / J

Stacktrace:

Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/flask/app.py", line 2292, in wsgi_app
response = self.full_dispatch_request()
File "/usr/lib/python3/dist-packages/flask/app.py", line 1815, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/jeth/.local/lib/python3.7/site-packages/flask_cors/extension.py", line 165, in wrapped_function
return cors_after_request(app.make_response(f(*args, **kwargs)))
File "/usr/lib/python3/dist-packages/flask/app.py", line 1718, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/lib/python3/dist-packages/flask/_compat.py", line 35, in reraise
raise value
File "/usr/lib/python3/dist-packages/flask/app.py", line 1813, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/lib/python3/dist-packages/flask/app.py", line 1799, in dispatch_request
return self.view_functionsrule.endpoint
File "/home/jeth/apps/asus-router-monitor-rest/app.py", line 45, in onlineClients
return ar.get_online_clients()
File "/home/jeth/apps/asus-router-monitor-rest/asus_router.py", line 262, in get_online_clients
for c in clnts['get_clientlist']:
KeyError: 'get_clientlist'