ansible.cfg: Removed settings that had default values

Our ansible.cfg had some settings that were using the default values,
according to ansible documentation.

ansible.cfg

@@ -2,9 +2,6 @@
 inventory = hosts
 library = library
 remote_tmp = $HOME/.ansible/tmp
-transport = smart
-remote_port = 22
-gathering = implicit
 remote_user = root
 nocows = 1
 roles_path = roles