For building suggest in elasticsearch, the safeContent field will be splitted into arrays. If the page is renamed or moved, the server will throw error: "Cannot read property 'split' of Undefined", and the index will be broken. Here two lines are added to fix this issue.
* Feature: Custom configuration for elasticsearch
For better search results especially in Chinese, which the standard token analyzer may not work well.
* Set default analyzer in settings when building index
* Remove dangling comma