detached/action.yml: synchronize with action.yml

There was a difference in whitespace, caught by the new step in
`checkin.yml`.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

detached/action.yml

@@ -64,4 +64,3 @@ outputs:
     description: 'The raw SSH address without the "ssh" prefix (only set when detached mode is enabled)'
   web-url:
     description: 'The web URL to connect to the tmate session (only set when detached mode is enabled and web URL is available)'
-