Print an error if cloning a http repo and NO_CURL is set

If Git is compiled with NO_CURL=YesPlease and one tries to
clone a http repository, git-clone tries to call the curl
binary. This trivial patch prints an error instead in such
situation.

Signed-off-by: Fernando J. Pereda <ferdy@gentoo.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/Makefile b/Makefile
index d40aa6a..648469e 100644
--- a/Makefile
+++ b/Makefile
@@ -419,6 +419,7 @@
 	rm -f $@
 	sed -e '1s|#!.*/sh|#!$(call shq,$(SHELL_PATH))|' \
 	    -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
+	    -e 's/@@NO_CURL@@/$(NO_CURL)/g' \
 	    $@.sh >$@
 	chmod +x $@