missing comma

-------
cc: @ggailey777

Author: ahmelsayed

articles/azure-functions/functions-host-json.md

@@ -194,7 +194,7 @@ Controls the logging behaviors of the function app, including Application Insigh
 
 ```json
 "logging": {
-    "fileLoggingMode": "debugOnly"
+    "fileLoggingMode": "debugOnly",
     "logLevel": {
       "Function.MyFunction": "Information",
       "default": "None"