Contribs: mpg123, don't build programs

This failed on Android, for example

contrib/src/mpg123/no-programs.patch

+--- mpg123/Makefile.am	2014-09-28 23:27:28.000000000 +0200
++++ mpg123.new/Makefile.am	2014-12-01 19:26:28.156173697 +0100
+@@ -6,7 +6,7 @@
+ ## initially written by Nicholas J. Humfrey
+ dist_man_MANS = man1/mpg123.1 man1/out123.1
+ 
+-SUBDIRS = src doc
++SUBDIRS = src/libmpg123 doc
+ DIST_SUBDIRS = src doc
+ ACLOCAL_AMFLAGS = -I m4
+ 

contrib/src/mpg123/rules.mak

@@ -14,6 +14,7 @@ $(TARBALLS)/mpg123-$(MPG123_VERSION).tar.bz2:
 
 mpg123: mpg123-$(MPG123_VERSION).tar.bz2 .sum-mpg123
 	$(UNPACK)
+	$(APPLY) $(SRC)/mpg123/no-programs.patch
 	$(MOVE)
 
 .mpg123: mpg123