Removed i18n dependency from ensure settings module

refs https://linear.app/tryghost/issue/CORE-35/refactor-route-and-redirect-settings

- i18n is an old pattern we are getting rid of. By removing it here we get rid of an extra dependancy on frontend's "proxy" module

core/frontend/services/settings/ensure-settings.js

@@ -2,10 +2,14 @@ const fs = require('fs-extra');
 const Promise = require('bluebird');
 const path = require('path');
 const debug = require('@tryghost/debug')('frontend:services:settings:ensure-settings');
-const {i18n} = require('../proxy');
+const tpl = require('@tryghost/tpl');
 const errors = require('@tryghost/errors');
 const config = require('../../../shared/config');
 
+const messages = {
+    ensureSettings: 'Error trying to access settings files in {path}.'
+};
+
 /**
 * Makes sure file is in the `/content/settings` directory. If not, copy the default over.
  * @param {String} fileName - name of the setting file
@@ -31,7 +35,7 @@ module.exports = function ensureSettingsFile(fileName) {
         }).catch((error) => {
             // CASE: we might have a permission error, as we can't access the directory
             throw new errors.GhostError({
-                message: i18n.t('errors.services.settings.ensureSettings', {path: contentPath}),
+                message: tpl(messages.ensureSettings, {path: contentPath}),
                 err: error,
                 context: error.path
             });

core/shared/i18n/translations/en.json

@@ -545,8 +545,7 @@
                     "help": "Check your {file} file for typos and fix the named issues.",
                     "validate": "The following definition \"{at}\" is invalid: {reason}"
                 },
-                "loader": "Error trying to load YAML setting for {setting} from '{path}'.",
-                "ensureSettings": "Error trying to access settings files in {path}."
+                "loader": "Error trying to load YAML setting for {setting} from '{path}'."
             },
             "mega": {
                 "requestFailed": {