remove a check that is no longer reachable

the DH params are checked in dh_parameters_from_numbers now

Author: reaperhulk

src/rust/src/backend/dh.rs

@@ -421,14 +421,6 @@ impl DHPrivateNumbers {
         let priv_key = utils::py_int_to_bn(py, self.x.bind(py))?;
 
         let dh = dh.set_key(pub_key, priv_key)?;
-        if !dh.check_key()? {
-            return Err(CryptographyError::from(
-                pyo3::exceptions::PyValueError::new_err(
-                    "DH private numbers did not pass safety checks.",
-                ),
-            ));
-        }
-
         let pkey = openssl::pkey::PKey::from_dh(dh)?;
         Ok(DHPrivateKey { pkey })
     }