FIX: restore "every email" default for old accounts in mailing list mode

- Change default for mailing list mode frequency to daily
- Remove bootbox warning for mailing list mode (cause default is daily)

app/assets/javascripts/discourse/controllers/preferences.js.es6

@@ -130,21 +130,6 @@ export default Ember.Controller.extend(CanCheckEmails, {
 
   actions: {
 
-    checkMailingList(){
-      Em.run.next(()=>{
-        const postsPerDay = this.get('model.mailing_list_posts_per_day');
-        if (!postsPerDay || postsPerDay < 2) {
-          return true;
-        }
-
-        bootbox.confirm(I18n.t("user.enable_mailing_list", {count: postsPerDay}), I18n.t("no_value"), I18n.t("yes_value"), (success) => {
-          if (!success) {
-            this.set('model.user_option.mailing_list_mode', false);
-          }
-        });
-      });
-    },
-
     save() {
       this.set('saved', false);
 

app/assets/javascripts/discourse/templates/user/preferences.hbs

@@ -203,7 +203,7 @@
     {{#unless siteSettings.disable_mailing_list_mode}}
       <div class='control-group pref-mailing-list-mode'>
         <label class="control-label">{{i18n 'user.mailing_list_mode.label'}}</label>
-        {{preference-checkbox labelKey="user.mailing_list_mode.enabled" warning="checkMailingList" checked=model.user_option.mailing_list_mode}}
+        {{preference-checkbox labelKey="user.mailing_list_mode.enabled" checked=model.user_option.mailing_list_mode}}
         <div class='instructions'>{{{i18n 'user.mailing_list_mode.instructions'}}}</div>
         {{#if model.user_option.mailing_list_mode}}
           <div class='controls controls-dropdown'>