execnever comes back. All you put after the call execis the dead code.
Delete execor put it in front of your line phpif this is the last thing to do. (And after checking for errors, if necessary, obviously.)
So for example
...
git-update-server-info
exec php /path/to/directory/file.php
Or just plain
...
git-update-server-info
php /path/to/directory/file.php
( , php script git.)