Fix flake8 error caused by using type instead of isinstance

Change-Id: Iccbf5a3a61e7b1c76c8e4e062fd8c24a09a39314
Signed-off-by: gatici <gulsum.atici@canonical.com>
(cherry picked from commit d7debb9afcbfe0fb1c112ea0834458753ffe34b1)
diff --git a/osm_nbi/descriptor_topics.py b/osm_nbi/descriptor_topics.py
index 1930254..a2c17ee 100644
--- a/osm_nbi/descriptor_topics.py
+++ b/osm_nbi/descriptor_topics.py
@@ -557,7 +557,7 @@
         # to preserve current expected behaviour
         if "userDefinedData" in indata:
             data = indata.pop("userDefinedData")
-            if type(data) == dict:
+            if isinstance(data, dict):
                 indata["_admin"]["userDefinedData"] = data
             else:
                 raise EngineException(
@@ -1182,7 +1182,7 @@
         # to preserve current expected behaviour
         if "userDefinedData" in indata:
             data = indata.pop("userDefinedData")
-            if type(data) == dict:
+            if isinstance(data, dict):
                 indata["_admin"]["userDefinedData"] = data
             else:
                 raise EngineException(