Update PrepareUserMessage function to include replyToUid parameter

pb/messages.proto

@@ -159,7 +159,7 @@ message UserMessage {
 	string from = 2; // My public key for that contact
 	string type = 3; 
 	bytes data = 4; 
-    ConversationStatus Status = 5;
+    ConversationStatus status = 5;
     ContactCard contact = 6;
     ServerCard knownServers = 7;
     Group group = 8;