[Grouple] Handle Usagi redirects

src/main/kotlin/org/koitharu/kotatsu/parsers/site/ru/grouple/GroupleParser.kt

@@ -310,6 +310,7 @@ internal abstract class GroupleParser(
 		in MintMangaParser.domains -> MangaParserSource.MINTMANGA
 		in ReadmangaParser.domains -> MangaParserSource.READMANGA_RU
 		in SelfMangaParser.domains -> MangaParserSource.SELFMANGA
+		in UsagiParser.domains -> MangaParserSource.USAGI
 		else -> source
 	}