pjsip.conf: privkey_file should be priv_key_file, mediaencryption=yes should be mediaencryption=sdes

privkey_file was missed in the snake case update. An example included an invalid value for the mediaencryption option.


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@414780 f38db490-d61c-443f-a65b-d21fe96a405b