Fix #802 - don't continue display update if we don't have a client ob…

…ject.

Changelog8.html

@@ -62,6 +62,7 @@ <h2><a name="v8.3.0" id="v8.3.0"></a>Version 8.3.0</h2>
 		<li><a href="https://github.com/Logitech/slimserver/pull/767">#767</a> - fix compatibility with standards compliant cometd libraries (thanks lynniemagoo!)</li>
 		<li><a href="https://github.com/Logitech/slimserver-vendor/issues/95">#95</a> - update faad helper binaries to fix a crash when the decoder call fails (thanks ralphy!)</li>
 		<li><a href="https://github.com/Logitech/slimserver/pull/777">#777</a> - When syncing with disconnected player through CLI, random player is synced</li>
+		<li><a href="https://github.com/Logitech/slimserver/issues/802">#802</a> - Log is flodded with callback warnings "Can't call method "display" on an undefined value"</li>
 		<li>Prevent a server crash while re-building the fulltext search index with huge collections.</li>
 		<li>Don't show online only artists when a virtual library view tells us to do so.</li>
 		<li>Fix IO::Socket::SSL initialization in the scanner's sync http lookup code.</li>