Fix coverage test after updating pip dependencies

Change-Id: Ifd299013d8ffa9d4098e96984b9eed9568d36fdd
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osm_nbi/tests/test_admin_topics.py b/osm_nbi/tests/test_admin_topics.py
index 0aeed61..4da4d61 100755
--- a/osm_nbi/tests/test_admin_topics.py
+++ b/osm_nbi/tests/test_admin_topics.py
@@ -915,7 +915,7 @@
             )
             self.assertIn(
                 "format error at '{}' '{}'".format(
-                    "projects", "{} is too short"
+                    "projects", "{} should be non-empty"
                 ).format([]),
                 norm(str(e.exception)),
                 "Wrong exception text",