Fixes #4361: Set correct type of connection_state

docs/release-notes/version-2.8.md

@@ -4,6 +4,7 @@
 
 ### Bug Fixes
 
+* [#4361](https://github.com/netbox-community/netbox/issues/4361) - Fix Type of `connection_state` in swagger schema.
 * [#4489](https://github.com/netbox-community/netbox/issues/4489) - Fix display of parent/child role on device type view
 
 ---

netbox/utilities/custom_inspectors.py

@@ -92,7 +92,7 @@ class CustomChoiceFieldInspector(FieldInspector):
                 value_schema = openapi.Schema(type=schema_type, enum=choice_value)
                 value_schema['x-nullable'] = True
 
-            if isinstance(choice_value[0], int):
+            if all(type(x) == int for x in [c for c in choice_value if c is not None]):
                 # Change value_schema for IPAddressFamilyChoices, RackWidthChoices
                 value_schema = openapi.Schema(type=openapi.TYPE_INTEGER, enum=choice_value)