TT#121500 fix missing mos_data in /api/conversations

Change-Id: Ia0a549a96d1fd311021a474d5098b1ab859e5a31
(cherry picked from commit 2afa637f4170214bf6654343c81983fb78d9bf8a)

lib/NGCP/Panel/Utils/CallList.pm

@@ -51,7 +51,7 @@ sub process_cdr_item {
     $params //= $c->req->params;
 
     map { $resource->{$_} = $item->get_column($_); } qw/id call_id call_type/;
-    if (my $mos_data = $item->cdr_mos_data) {
+    if ($item->can('cdr_mos_data') and (my $mos_data = $item->cdr_mos_data)) {
         my %mos_data_res = $mos_data->get_inflated_columns;
         map { $resource->{$_} = $mos_data_res{$_}; } qw/mos_average mos_average_packetloss mos_average_jitter mos_average_roundtrip/;
     }