Makefile: git-http-fetch does not need expat

This appears to be a bad cut-and-paste in commit 1088261f.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1489,7 +1489,7 @@ http.o http-walker.o: $(LIB_H)
 
 git-http-fetch$X: revision.o http.o http-walker.o http-fetch.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
-		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
+		$(LIBS) $(CURL_LIBCURL)
 git-http-push$X: revision.o http.o http-push.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)