TT#76552 send_template: log mail sending actions

We need to trace sending mails to be able to track down
possibly not sent mails, see e.g. MT#31936.

Use quotesensitive to not leak from/to information into logs,
but handle this properly to ensure we're GDPR safe.

Change-Id: I4d09d073e12b1dd61053956252b59ad06a29d59d

lib/NGCP/Panel/Utils/Email.pm

@@ -30,6 +30,8 @@ sub send_template {
     my ($c, $vars, $subject, $body, $from, $to) = @_;
     my $t = Template->new;
 
+    $c->log->info("Trying to send mail from '" . $c->qs($from) . "' to '" . $c->qs($to) . "'");
+
     my $processed_body = "";
     $t->process(\$body, $vars, \$processed_body) || 
         die "error processing email template body, type=".$t->error->type.", info='".$t->error->info."'";
@@ -58,6 +60,8 @@ sub send_template {
     #    to => $template_processed->{to},
     #);
 
+    $c->log->info("Successfully handed over mail from '" . $c->qs($from) . "' to '" . $c->qs($to) . "'");
+
     return 1;
 }