Remove duplicate entry from ExtensionInfo struct

chrome/common/extensions/api/extension_api.json

 [
   {
     "namespace": "extension",
     "unprivileged": true,
     "types": [
       {
         "id": "MessageSender",
         "type": "object",
         "description": "An object containing information about the script context that sent a message or request.",
         "properties": {
@@ skipping 4016 matching lines @@
             "type": "string"
           },
           "version": {
             "description": "The <a href='manifest.html#version'>version</a> of this extension or app.",
             "type": "string"
           },
           "enabled": {
             "description": "Whether it is currently enabled or disabled.",
             "type": "boolean"
           },
-          "enabled": {
-            "description": "Whether it is currently enabled or disabled.",
-            "type": "boolean"
-          },
           "isApp": {
             "description": "True if this is an app.",
             "type": "boolean"
           },
           "appLaunchUrl": {
             "description": "The launch url (only present for apps).",
             "type": "string",
             "optional": true
           },
           "optionsUrl": {
@@ skipping 210 matching lines @@
                   "token": { "type": "string", "optional": true }
                 }
               }
             ]
           }
         ]
       }
     ]
   }
 ]