Fix typo

split は不規則動詞

src/misc/acct/parse.ts

@@ -1,5 +1,5 @@
 export default (acct: string) => {
 	if (acct.startsWith('@')) acct = acct.substr(1);
-	const splitted = acct.split('@', 2);
+	const split = acct.split('@', 2);
-	return { username: splitted[0], host: splitted[1] || null };
+	return { username: split[0], host: split[1] || null };
 };