Update to zrtp4j-light v3.1.0

Update zrtp4j-light that implements new features to negotiate ZRP protocol
versions, support the B256 SAS authentication mode, some smaller updates and
bug fixes.

git-svn-id: https://svn.java.net/svn/jitsi~svn/libjitsi@10639 198c5059-ef06-4ec0-9a75-fdd6b0ef00a6