"View Changes" since last review button only works once (#7228) (#7229)

Fixes #7182

Author: alexr00

src/github/pullRequestOverview.ts

@@ -390,7 +390,11 @@ export class PullRequestOverviewPanel extends IssueOverviewPanel<PullRequestMode
 	}
 
 	private gotoChangesSinceReview(message: IRequestMessage<void>): Promise<void> {
-		this._item.showChangesSinceReview = true;
+		if (!this._item.showChangesSinceReview) {
+			this._item.showChangesSinceReview = true;
+		} else {
+			PullRequestModel.openChanges(this._folderRepositoryManager, this._item);
+		}
 		return this._replyMessage(message, {});
 	}