Trivial: Use 'SSH' rather than 'Ssh'

This is reflected in the '--help' screen.

Change-Id: Ic22a65ff6a56b069b37a0ea8365cce2b3f93621c

Author: stephenfin

doc/source/command-objects/server.rst

@@ -614,7 +614,7 @@ Show server details
 server ssh
 ----------
 
-Ssh to server
+SSH to server
 
 .. program:: server ssh
 .. code:: bash

openstackclient/compute/v2/server.py

@@ -1445,7 +1445,7 @@ def take_action(self, parsed_args):
 
 
 class SshServer(command.Command):
-    """Ssh to server"""
+    """SSH to server"""
 
     def get_parser(self, prog_name):
         parser = super(SshServer, self).get_parser(prog_name)