fix: Increase wait time if wayland socket is missing
Waiting for half a second spams the log in case of a mir-kiosk refresh; two seconds is fine as it’s still quite fast after the socket is available again.
When the wayland socket is deleted and away for a longer period (e.g. during a snap refresh of mir-kiosk instead of a simple service restart), we should wait for the socket to reoccur before we restart the browser.
Add a wait condition in case the wayland socket is not ready yet. Using the DELETE_SELF event on the socket itself lead to race conditions where inotifywait seemed to listen, but probably to an outdated inode. The sleep delay should ensure that the browser is restarted after mir-kiosk is up again.
