Fix link preview migration issue

Session/Signal/AppDelegate.m

@@ -166,6 +166,10 @@ static NSTimeInterval launchStartedAt;
 
     [LKAppModeManager configureWithDelegate:self];
 
+    // OWSLinkPreview is now in SessionMessagingKit, so to still be able to deserialize link previews we
+    // need to tell NSKeyedUnarchiver about the change.
+    [NSKeyedUnarchiver setClass:OWSLinkPreview.class forClassName:@"SessionServiceKit.OWSLinkPreview"];
+
     BOOL isLoggingEnabled;
 #ifdef DEBUG
     // Specified at Product -> Scheme -> Edit Scheme -> Test -> Arguments -> Environment to avoid things like

SessionMessagingKit/Messages/Signal/TSMessage.m

@@ -79,7 +79,7 @@ const NSUInteger kOversizeTextMessageSizeThreshold = 2 * 1024;
     [self updateExpiresAt];
     _quotedMessage = quotedMessage;
     _linkPreview = linkPreview;
-    _openGroupServerMessageID = -1;
+    _openGroupServerMessageID = 0;
 
     return self;
 }