Function nginx::SSL_CTX_set_alpn_select_cb

pub unsafe extern "C" fn SSL_CTX_set_alpn_select_cb(
    ctx: *mut SSL_CTX, 
    cb: Option<unsafe extern "C" fn(ssl: *mut SSL, out: *mut *const c_uchar, outlen: *mut c_uchar, in_: *const c_uchar, inlen: c_uint, arg: *mut c_void) -> c_int>, 
    arg: *mut c_void
)