Fix rockspec deploy formatting

Author: alerque

Makefile

@@ -52,7 +52,7 @@ rockspecs/$(PACKAGE)-%-0.rockspec: TAG = v$*
 rockspecs/$(PACKAGE)-%-0.rockspec: $(PACKAGE).rockspec.in
 	$(rockpec_template)
 	sed -i \
-		-e '/rockspec-format/s/3.0/1.0/' \
+		-e '/rockspec_format/s/3.0/1.0/' \
 		-e '/url = "git/a\   dir = "fluent.lua",' \
 		-e '/issues_url/d' \
 		-e '/maintainer/d' \