regtok new cmd: Use -n for --token

as mentioned in PR #42

synadm/cli/regtok.py

@@ -78,7 +78,7 @@ def regtok_details_cmd(helper, token, datetime):
 
 @regtok.command(name="new")
 @click.option(
-    "--token", "-t", type=str, default=None,
+    "--token", "-n", type=str, default=None,
     help="""Set the registration token. The default is a random value
     generated by the server.""")
 @click.option(