res_musiconhold.c: Remove obsolete REF_DEBUG code.

Remove unneeded code that writes to the wrong file location in an obsolete
format.
........

Merged revisions 421799 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/11@421800 f38db490-d61c-443f-a65b-d21fe96a405b