MT#62223 API unhandled internal errors cause 500 error

* unhandled internal errors (such as DBI error) are now properly
  returned as 500 Internal Server Error instead of 200 OK

Change-Id: Iabc80cd200c9091dd249bc90aa586d5d7b616b69
(cherry picked from commit cbc4e57d45)
(cherry picked from commit d0c8c42d28)

lib/NGCP/Panel/Role/API.pm

@@ -1071,6 +1071,18 @@ sub log_response {
         $errors = $c->stash->{is_api_error_response}
                     ? join ', ', splice @{$c->error}, 1
                     : join ', ', @{$c->error};
+
+        # unhandled error message, should return 500 instead of 200
+        if ($c->response->status == 200) {
+            my $code = HTTP_INTERNAL_SERVER_ERROR;
+            $c->response->content_type('application/json');
+            $c->response->status($code);
+            $c->response->body(JSON::to_json({
+                code => $code,
+                message => "Internal Server Error" })."\n"
+            );
+        }
+
         $c->clear_errors;
     }
     my ($response_body, $params_data) = $self->filter_log_response(