Updated changelog for a fix I did yesterday

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@1935 f5dc347c-c33d-0410-90a0-b07cc1902cb9

doc/ChangeLog

@@ -9,6 +9,7 @@ Mantis ChangeLog
  * Fix: #2937: 'Double quotes not handled correctly in version names'
  * Fix: #2936: 'SYSTEM WARNING: ob_gzhandler() used twice'
  * Fix: #2941: Checking that project upload path exists and is writable to webserver
+ * Fix: #2943: Document title should be mandatory
  * Fix: lang_api did not load the user's preferred language
  * Fix: obscure error when database connect failed
  * Fix: error when deleting news items