Fix bug 2155 to resolve issues with IETF L2VPN WIM connector

Change-Id: If03acb8469f36bbca51a936bfb0808ec0124468f
Signed-off-by: gifrerenom <lluis.gifre@cttc.es>
diff --git a/NG-RO/osm_ng_ro/ns_thread.py b/NG-RO/osm_ng_ro/ns_thread.py
index cb52d77..0ca2cb2 100644
--- a/NG-RO/osm_ng_ro/ns_thread.py
+++ b/NG-RO/osm_ng_ro/ns_thread.py
@@ -1837,7 +1837,10 @@
                 wim = deepcopy(vim)
                 wim_config = wim.pop("config", {}) or {}
                 wim["uuid"] = wim["_id"]
-                wim["wim_url"] = wim["url"]
+                if "url" in wim and "wim_url" not in wim:
+                    wim["wim_url"] = wim["url"]
+                elif "url" not in wim and "wim_url" in wim:
+                    wim["url"] = wim["wim_url"]
 
                 if wim.get("dpid"):
                     wim_config["dpid"] = wim.pop("dpid")