Replace current verbose GPL stuff in libbb/*.c with one-line GPL boilerplate.

libbb/md5.c

@@ -12,6 +12,7 @@
  *
  *  Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
+
 #include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>