if we don't have a stored diaspora author signature which has been passed the baton since the post's creation, fill in the field with their redmatrix signature. It's pointless, but there's so much pointless stuff in here that I doubt it matters. From what I can ascertain - nobody is going to look at it anyway.

include/diaspora.php

@@ -2568,6 +2568,7 @@ function diaspora_send_relay($item,$owner,$contact,$public_batch = false) {
 		// Author signature information (for likes, comments, and retractions of likes or comments,
 		// whether from Diaspora or Friendica) must be placed in the `sign` table before this 
 		// function is called
+		$authorsig = $item['sig'];
 		logger('diaspora_send_relay: original author signature not found, cannot send relayable');
 // ignore - see below
 //		return;