{Pylint} Fix `unused-import` (#17999)

pylintrc

@@ -36,7 +36,6 @@ disable=
     too-many-lines,
     unnecessary-comprehension,
     unrecognized-inline-option,
-    unused-import,
     use-a-generator,
     using-constant-test,
     wrong-import-order,

src/azure-cli/azure/cli/command_modules/cdn/custom/custom_waf.py

@@ -21,8 +21,6 @@ def show_endpoint_waf_policy_link(client: EndpointsOperations,
                                   profile_name: str,
                                   endpoint_name: str):
 
-    from azure.mgmt.cdn.models import (EndpointPropertiesUpdateParametersWebApplicationFirewallPolicyLink)
-
     link = client.get(resource_group_name, profile_name, endpoint_name).web_application_firewall_policy_link
     if link is not None:
         return link