contact_processing.php: fix PHP error
contact_processing.php: fix PHP error

Missing semi-colon was introduced when converting to PHPMailer in
62fb3bb407268e6ad071e286b2651d726b38c9b7.

smrealms/smr,hemberger/smr,smrealms/smr,smrealms/smr,hemberger/smr,hemberger/smr,hemberger/smr