remove announcement

src/core/bg/index.js

@@ -79,12 +79,4 @@ browser.runtime.onMessage.addListener((message, sender) => {
 
 if (browser.runtime.onMessageExternal) {
 	browser.runtime.onMessageExternal.addListener(externalMesssages.onMessage);
-}
-
-browser.runtime.onInstalled.addListener((details) => {
-	if (details.reason == "update" && details.previousVersion.startsWith("1.21")) {
-		browser.tabs.create({
-			url: "https://gildas-lormeau.github.io/singlefile-updates/version-1-22.html"
-		});
-	}
-});
+}