Fixed main server client initialization

This fixes the usage of the singleton client class which
houses/creates the aprslib client.  We were getting multiple
logins, now we get one.

aprsd/main.py

@@ -430,7 +430,7 @@ def server(
     plugin_manager.setup_plugins()
     try:
         cl = client.Client(config)
-        cl.setup_connection()
+        cl.client
     except LoginError:
         sys.exit(-1)