Updating Composer dependencies

This will update the password_compat library and Symfony YAML Component
Removed unreachable code

exit() terminates execution of the script.
Shutdown functions and object destructors will always be executed, but there is no chance to execute $app->close(0);
Merge pull request #5226 from demis-palma/patch-6

Removed unreachable code
Merge pull request #5163 from mbabker/ComposerUpdates

Updating Composer dependencies
[fix] Who's online module shows multiple entries for a user name. Fixes #5111