Removed obsolete isset()
Removed obsolete isset()

Unset wont do anything in case var/array/offset doesn't exist.
iFixit/php-code-coverage,Koc/php-code-coverage,kelunik/php-code-coverage,sebastianbergmann/php-code-coverage,sebastianbergmann/php-code-coverage,theseer/php-code-coverage,sebastianbergmann/php-code-coverage,theseer/php-code-coverage,theseer/php-code-coverage