fix when omitting variable in catch clause

[bramstroker]

Using the following construct:

try {
} catch (\My\Namespace\MyException) {
}

Results in:

1 | ERROR | Namespace for "<?php" class is not specified.

This PR fixes this so both scenarios with a variable or without variable in the catch clause will work.

[pmzandbergen]

Note: This is supported on PHP >= 8.0.0

See https://www.php.net/manual/en/language.exceptions.php

As of PHP 8.0.0, the variable name for a caught exception is optional. If not specified, the catch block will still execute but will not have access to the thrown object.