Remove unnecessary define for Solaris

(closes issue #15358)
 Reported by: snuffy
 Patches: 
       bug_res_moh_remove_unneeded_include.diff uploaded by snuffy (license 35)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@214611 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_musiconhold.c

@@ -42,9 +42,6 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include <sys/stat.h>
 #include <dirent.h>
 #include <sys/ioctl.h>
-#ifdef SOLARIS
-#include <thread.h>
-#endif
 
 #ifdef HAVE_DAHDI
 #include <dahdi/user.h>