Fix 1475 - Incorrect description in instantiating error

Change-Id: I099c07f8a66400fa4d3130d6234dd17867ad387f
Signed-off-by: sousaedu <eduardo.sousa@canonical.com>
diff --git a/NG-RO/osm_ng_ro/ns_thread.py b/NG-RO/osm_ng_ro/ns_thread.py
index 681128e..5df74c5 100644
--- a/NG-RO/osm_ng_ro/ns_thread.py
+++ b/NG-RO/osm_ng_ro/ns_thread.py
@@ -596,7 +596,7 @@
                     )
                 elif len(vim_images) > 1:
                     raise NsWorkerException(
-                        "More than one network found with this criteria: '{}'".format(
+                        "More than one image found with this criteria: '{}'".format(
                             task["find_params"]
                         )
                     )