ssb: Don't show messages that were slow to load from another channel.

apps/ssb/tf-tab-news-feed.js

@@ -386,6 +386,7 @@ class TfTabNewsFeedElement extends LitElement {
 		let self = this;
 		this.loading++;
 		let messages = [];
+		let original_hash = this.hash;
 		try {
 			if (this._messages_hash !== this.hash) {
 				this.messages = [];
@@ -407,7 +408,9 @@ class TfTabNewsFeedElement extends LitElement {
 		} finally {
 			this.loading--;
 		}
-		this.messages = this.merge_messages(this.messages, messages);
+		if (this.hash == original_hash) {
+			this.messages = this.merge_messages(this.messages, messages);
+		}
 		this.time_loading = undefined;
 		console.log(
 			`loading ${messages.length} messages done for ${self.whoami} in ${(new Date() - start_time) / 1000}s`