Escape newlines in hold messages. #7395
Escape newlines in hold messages. #7395

The FTO should be careful about excluding newlines from hold messages,
as these characters are banned by the schedd and cause the entire update
to be dropped.  With this change, a newline character becomes the two
character sequence `\n`.

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor