Remove unused svg and improve 'make svg-check' (#12311)

- Remove unused source SVG gitea-settings (it was changed to ociticon)
- Improve 'make svg-check' to also detect added files

Makefile

@@ -628,9 +628,10 @@ svg: node-check | node_modules
 
 .PHONY: svg-check
 svg-check: svg
-	@diff=$$(git diff $(SVG_DEST_DIR)); \
+	@git add $(SVG_DEST_DIR)
+	@diff=$$(git diff --cached $(SVG_DEST_DIR)); \
 	if [ -n "$$diff" ]; then \
-		echo "Please run 'make svg' and commit the result:"; \
+		echo "Please run 'make svg' and 'git add $(SVG_DEST_DIR)' and commit the result:"; \
 		echo "$${diff}"; \
 		exit 1; \
 	fi;

web_src/svg/gitea-settings.svg

@@ -1 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><path d="M32 448h64v-96H32v96zM96 64H32v160h64V64zm160 0h-64v64h64V64zM0 320h128v-64H0v64zm192 128h64V256h-64v192zm-32-224h128v-64H160v64zM416 64h-64v192h64V64zm-96 224v64h128v-64H320zm32 160h64v-64h-64v64z"/></svg>