Check for reply existence before using its values in Model\Mail
Check for reply existence before using its values in Model\Mail

- Address https://github.com/friendica/friendica/issues/10474#issuecomment-925263894

friendica/friendica,friendica/friendica,annando/friendica,tobiasd/friendica,annando/friendica,tobiasd/friendica,friendica/friendica,annando/friendica,annando/friendica,annando/friendica,friendica/friendica,friendica/friendica,tobiasd/friendica,tobiasd/friendica,tobiasd/friendica