GitLab::API: Allow subclasses in AUTOLOAD

GitLab/API.pm

@@ -454,10 +454,10 @@ sub AUTOLOAD {
     $method =~ s/.*:://g;
 
     croak "Not a GitLab::API instance"
-        unless (blessed($self) // "") eq __PACKAGE__;
+        if !blessed($self) || !$self->isa(__PACKAGE__);
 
     croak "Unknown method '$AUTOLOAD' called"
-        unless defined $methods{$method};
+        if !defined $methods{$method};
 
     $log->debug("autoloading method '$method'");