post-hover.js: fix long loop

js/post-hover.js

@@ -30,8 +30,11 @@ onready(function(){
 		}
 		
 		var board = $(this);
+		var i = 0;
 		while (board.data('board') === undefined) {
 			board = board.parent();
+			i++;
+			if (i >= 10) return;
 		}
 		var threadid;
 		if ($link.is('[data-thread]')) threadid = 0;