Fix bug, check VF is active before destroy

Change-Id: Id589ab96fad5a4c1af876e03a0f27586b2af7695
Signed-off-by: mirabal <leonardo.mirabal@altran.com>
diff --git a/osm_openvim/host_thread.py b/osm_openvim/host_thread.py
index 1f8fdb4..80d9986 100644
--- a/osm_openvim/host_thread.py
+++ b/osm_openvim/host_thread.py
@@ -1901,7 +1901,8 @@
             #TODO.Revise  self.server_forceoff(True)
 
             iface = conn.interfaceLookupByMACString(mac)
-            iface.destroy()
+            if iface.isActive():
+                iface.destroy()
             iface.create()
             self.logger.debug("restore_iface '%s' %s", name, mac)
         except host_thread.lvirt_module.libvirtError as e: