fix typos in README
fix typos in README
cuijinquan/libsrtp,cuijinquan/libsrtp,ksophocleous/libsrtp,ksophocleous/libsrtp,Distrotech/libsrtp,yarrcc/libsrtp-ios,persmule/libsrtp,cuijinquan/libsrtp,yarrcc/libsrtp-ios,yarrcc/libsrtp-ios,Distrotech/libsrtp,persmule/libsrtp,persmule/libsrtp