hyprctl: fixed false example

[rexept]

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page(s) have at most 8 examples.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The page(s) follow the style guide.
• The PR title conforms to the recommended templates.
• Version of the command being documented (if known):

The reason for this is that the old 'exec {{app}}' is too specific.

'exec' doesn't have to be the dispatcher it could be a lot of other things too.