Makefile: fix header dependency checker to allow NO_CURL builds

Do not expect to find http-related dependency fragments after a build
with HTTP support disabled.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1656,7 +1656,10 @@ git.o git.spec \
 
 TEST_OBJS := $(patsubst test-%$X,test-%.o,$(TEST_PROGRAMS))
 GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(PROGRAM_OBJS) $(TEST_OBJS) \
-	git.o http.o http-walker.o remote-curl.o
+	git.o
+ifndef NO_CURL
+	GIT_OBJS += http.o http-walker.o remote-curl.o
+endif
 XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
 OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)