[WebUI][Servers] Remove code to load non existing file.

hatohol_server_edit_dialog.js has been removed from the repository.
Althogh the line causes an error, many browsers seem to ignore it.
So any problem has appered since the file was deleted.
Merge pull request #619 from project-hatohol/remove-loading-of-unused-js-file

[WebUI][Servers] Remove code to load non existing file.