bug_report_processing.php: add subject to message
bug_report_processing.php: add subject to message

The player bug reports get sent to the admin message boxes, which are
not stored with a "subject" field. Add the subject to the message body
so that the subject line is not lost!

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