Removing "#include <sys/timeb.h>" from my_global.h,

which has been removed earlier, but somehow got into the sources again.

This file is not really needed, and it prints warnings
"sys/timeb.h is deprecated" for every file when compiling on FreeBSD.

include/my_global.h

@@ -344,9 +344,6 @@ C_MODE_END
 #ifdef HAVE_FCNTL_H
 #include <fcntl.h>
 #endif
-#ifdef HAVE_SYS_TIMEB_H
-#include <sys/timeb.h>				/* Avoid warnings on SCO */
-#endif
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif