Add a better solution for the ssh_known_hosts issue

Fix https://github.com/ansible/ansible/issues/10172 too

source_control/git.py

@@ -179,7 +179,8 @@ requirements:
 notes:
     - "If the task seems to be hanging, first verify remote host is in C(known_hosts).
       SSH will prompt user to authorize the first contact with a remote host.  To avoid this prompt, 
-      one solution is to add the remote host public key in C(/etc/ssh/ssh_known_hosts) before calling 
+      one solution is to use the option accept_hostkey. Another solution is to 
+      add the remote host public key in C(/etc/ssh/ssh_known_hosts) before calling 
       the git module, with the following command: ssh-keyscan -H remote_host.com >> /etc/ssh/ssh_known_hosts."
 '''