Remove OPENSSL_assert() from conf_api.c

Reviewed-by: NAndy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3740)

crypto/conf/conf_api.c

@@ -204,7 +204,8 @@ CONF_VALUE *_CONF_new_section(CONF *conf, const char *section)
     v->value = (char *)sk;
 
     vv = lh_CONF_VALUE_insert(conf->data, v);
-    OPENSSL_assert(vv == NULL);
+    if (vv != NULL)
+        goto err;
     return v;
 
  err: