Makefile: do not recompile main programs when libraries have changed.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Makefile

@@ -582,7 +582,7 @@ git-http-push$X: revision.o http.o http-push.o $(LIB_FILE)
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
 $(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
-$(patsubst git-%$X,%.o,$(PROGRAMS)): $(GITLIBS)
+$(patsubst git-%$X,%.o,$(PROGRAMS)): $(LIB_H) $(wildcard */*.h)
 $(DIFF_OBJS): diffcore.h
 
 $(LIB_FILE): $(LIB_OBJS)