Fix precedence problem by replacing or with ||

Created by: thibauthourlier

Since Perl 5.22, it warns of possible precedence problem it cases like : return $value or die('Sad'); return $value is tested, not $value. It can be fixed by either using || or by using () around the test. The problem was already there in earlier versions of Perl but no waring was issued.

Created by: thibauthourlier

I've made the changes requested, by adding an if statement and using confess instead of die