fixes description

Author: German Robayo Paz

src/aks-preview/azext_aks_preview/tests/latest/test_managed_cluster_decorator.py

@@ -4197,7 +4197,7 @@ def test_handle_enable_istio_cni(self):
         ))
 
     def test_handle_disable_istio_cni(self):
-        # Test enabling Istio CNI on existing ASM-enabled cluster
+        # Test disabling Istio CNI on existing ASM-enabled cluster
         ctx_0 = AKSPreviewManagedClusterContext(
             self.cmd,
             AKSManagedClusterParamDict(