Fix a minor issue resulting from #2935.

There is no longer a `pgwarning` key set on the controller object for
the `lib/WeBWorK/ContentGenerator/Problem.pm` module and never was a
`pgwarning` key for the returned pg object in the
`lib/ContentGenerator/GatewayQuiz.pm` module.  So use the correct key on
the returned pg object in both cases.  That is the `warning_messages`
key.

The warning messages were still being shown at the bottom, but not the
message at the top of the page notifying of the existence of those
warnings.  Since the warnings at the bottom might not be visible, the
warnings may be missed.

Author: drgrice1

lib/WeBWorK/ContentGenerator/GatewayQuiz.pm

@@ -1512,7 +1512,7 @@ async sub getProblemHTML ($c, $effectiveUser, $set, $formFields, $mergedProblem)
 		if $c->{can}{checkAnswers}
 		&& (!$c->{submitAnswers} || defined $c->param('problem_data_' . $mergedProblem->problem_id));
 
-	$c->stash->{haveProblemWarnings} = 1 if $pg->{warnings} || @{ $pg->{pgwarning} // [] };
+	$c->stash->{haveProblemWarnings} = 1 if $pg->{warnings} || @{ $pg->{warning_messages} // [] };
 
 	return $pg;
 }

templates/ContentGenerator/Problem.html.ep

@@ -65,7 +65,7 @@
 % stash->{footerWidthClass} = 'col-lg-10';
 %
 <%== $c->post_header_text =%>
-% if ($c->{pg}{warnings} || @{ $c->{pgwarning} // [] }) {
+% if ($c->{pg}{warnings} || @{ $c->{pg}{warning_messages} // [] }) {
 	<div class="row g-0 mb-2">
 		<div class="col-12 alert alert-danger m-0">
 			<%== maketext('<strong>Warning</strong>: There may be something wrong with this question. '