fix leak of keyfile_bytes
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index 04cb58b..f291352 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -2613,6 +2613,7 @@
     }
     SSL_CTX_set_default_passwd_cb(self->ctx, orig_passwd_cb);
     SSL_CTX_set_default_passwd_cb_userdata(self->ctx, orig_passwd_userdata);
+    Py_XDECREF(keyfile_bytes);
     PyMem_Free(pw_info.password);
     PyMem_Free(certfile_bytes);
     Py_RETURN_NONE;