Fix git hash injecting

Makefile

@@ -36,12 +36,12 @@ bin/%.html: bin/tmp
 bin/fc.js: bin/
 	devTools/concatFiles.sh js/ '*.js' $@
 
-bin/tmp: bin/fc.js src/gui/mainMenu/AlphaDisclaimer.tw
+bin/tmp: bin/fc.js injectGitCommitHash
 	$(TWEEGO) --module=bin/fc.js --head devTools/head.html src/ > $@
 	rm -f bin/fc.js
 
-src/gui/mainMenu/AlphaDisclaimer.tw:
-	sed -Ei "s/build: .releaseID/\0 commit $(COMMIT)/" $@
+injectGitCommitHash:
+	sed -Ei "s/build: .releaseID/\0, commit $(COMMIT)/" src/gui/mainMenu/AlphaDisclaimer.tw
 
 bin/:
 	mkdir -p $@