remove bogus readme
remove bogus readme

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