Purge MINGW_WINSOCK_LIBS config variable.

This was only needed for ntohl() function which has already been removed.

src/test_seeking/Makefile.am

@@ -22,13 +22,13 @@ EXTRA_DIST = \
 
 AM_CFLAGS = @OGG_CFLAGS@
 
-INCLUDES = 
+INCLUDES =
 
 noinst_PROGRAMS = test_seeking
 test_seeking_LDADD = \
 	$(top_builddir)/src/libFLAC/libFLAC.la \
 	@OGG_LIBS@ \
-	@MINGW_WINSOCK_LIBS@ \
 	-lm
+
 test_seeking_SOURCES = \
 	main.c