Fixed the following bug. When dialing *99 it produces this error.
2013-02-21 18:39:28.016638 [ERR] mod_lua.cpp:198 ...app/voicemail/resources/functions/record_message.lua:39: bad argument #1 to 'len' (string expected, got nil) 

git-svn-id: http://fusionpbx.googlecode.com/svn/trunk@3777 e2954ef0-caed-11de-bd98-e341d93cc3cc