Change "if not" into "unless", more perl-like

glv.pl

@@ -6,7 +6,7 @@ my @lines = `curl "https://gitlab.com/gitlab-org/gitlab-foss/-/raw/master/CHANGE
 foreach (@lines) {
     if (/^##\s+(\d+\.\d+\.\d+)\s+\((\d+-\d+-\d+)/) {
         print "$1 [$2]\n";
-        if (!$all) {
+        unless ($all) {
             last;
         }
     }