trim font family name

lib/single-file/rules-minifier.js

@@ -140,10 +140,11 @@ this.rulesMinifier = this.rulesMinifier || (() => {
 	function getFontFamily(fontFamily) {
 		fontFamily = fontFamily.toLowerCase().trim();
 		if (fontFamily.match(/^'(.*)'$/)) {
-			return fontFamily.replace(/^'(.*)'$/, "$1");
+			fontFamily = fontFamily.replace(/^'(.*)'$/, "$1");
 		} else {
-			return fontFamily.replace(/^"(.*)"$/, "$1");
+			fontFamily = fontFamily.replace(/^"(.*)"$/, "$1");
 		}
+		return fontFamily.trim();
 	}
 
 })();