don't remove fonts served with text/plain content-type if valid

Former-commit-id: 71729514661dbeaf1443432e3f0650cbb8549254

lib/single-file/modules/css-fonts-alt-minifier.js

@@ -41,7 +41,6 @@ this.singlefile.lib.modules.fontsAltMinifier = this.singlefile.lib.modules.fonts
 	const REGEXP_FONT_FORMAT_VALUE = /format\((.*?)\)\s*,?$/;
 	const REGEXP_FONT_SRC = /(.*?)\s*,?$/;
 	const EMPTY_URL_SOURCE = /^url\(["']?data:[^,]*,?["']?\)/;
-	const TEXT_CONTENT_URL_SOURCE = /^url\(["']?data:text\//;
 	const LOCAL_SOURCE = "local(";
 	const MEDIA_ALL = "all";
 	const FONT_WEIGHTS = {
@@ -213,7 +212,7 @@ this.singlefile.lib.modules.fontsAltMinifier = this.singlefile.lib.modules.fonts
 				source.valid = true;
 			}
 		}));
-		const findSource = (fontFormat, testValidity) => fontInfo.find(source => !source.src.match(EMPTY_URL_SOURCE) && !source.src.match(TEXT_CONTENT_URL_SOURCE) && source.format == fontFormat && (!testValidity || source.valid));
+		const findSource = (fontFormat, testValidity) => fontInfo.find(source => !source.src.match(EMPTY_URL_SOURCE) && source.format == fontFormat && (!testValidity || source.valid));
 		const filterSource = fontSource => fontInfo.filter(source => source == fontSource || source.src.startsWith(LOCAL_SOURCE));
 		stats.fonts.processed += fontInfo.length;
 		stats.fonts.discarded += fontInfo.length;