Contrib: delete the libdts.a symlink

It's useless for us and annoying on Windows

(cherry picked from commit b7f623c96a7cd243af3661842df5ee6d7ab0bcd6)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/dca/rules.mak

@@ -27,4 +27,5 @@ libdca: libdca-$(DCA_VERSION).tar.bz2 .sum-dca
 	cd $< && $(HOSTVARS) CFLAGS="$(CFLAGS) -std=gnu89" ./configure $(HOSTCONF)
 	cd $< && $(MAKE) -C include install
 	cd $< && $(MAKE) -C libdca install
+	rm -f $(PREFIX)/lib/libdts.a
 	touch $@