Adjust set_ssl_context API

    /// change the context corresponding to the current connection

    ///

    /// Returns a clone of the SslContext @ctx (ie: the new context). The old context is freed.

    pub fn set_ssl_context(&self, ctx: &SslContext) -> SslContext {

        // If duplication of @ctx's cert fails, this returns NULL. This _appears_ to only occur on

        // allocation failures (meaning panicing is probably appropriate), but it might be nice to

        // propogate the error.

        assert!(unsafe { ffi::SSL_set_SSL_CTX(self.ssl, ctx.ctx) } != ptr::null_mut());

        // FIXME: we return this reference here for compatibility, but it isn't actually required.

        // This should be removed when a api-incompatabile version is to be released.

        //

        // ffi:SSL_set_SSL_CTX() returns copy of the ctx pointer passed to it, so it's easier for

        // us to do the clone directly.

        ctx.clone()

    pub fn set_ssl_context(&self, ctx: &SslContext) -> Result<(), ErrorStack> {

        unsafe {

            try_ssl_null!(ffi::SSL_set_SSL_CTX(self.ssl, ctx.ctx));

        }

        Ok(())

    }

    /// obtain the context corresponding to the current connection