Fix reference in comment.
Fix reference in comment.

persmule/libsrtp,persmule/libsrtp,yarrcc/libsrtp-ios,ksophocleous/libsrtp,cuijinquan/libsrtp,yarrcc/libsrtp-ios,cuijinquan/libsrtp,yarrcc/libsrtp-ios,Distrotech/libsrtp,ksophocleous/libsrtp,persmule/libsrtp,cuijinquan/libsrtp,Distrotech/libsrtp