[FIX] mail: BS4, restore follower subtype style

Behavior is still broken and will be fixed in a future update.

addons/mail/static/src/js/followers.js

@@ -19,7 +19,7 @@ var Followers = AbstractField.extend({
         // click on '(Un)Follow' button, that toggles the follow for uid
         'click .o_followers_follow_button': '_onFollowButtonClicked',
         // click on a subtype, that (un)subscribes for this subtype
-        'click .o_subtypes_list input': '_onSubtypeClicked',
+        'click .o_subtypes_list .custom-checkbox': '_onSubtypeClicked',
         // click on 'invite' button, that opens the invite wizard
         'click .o_add_follower': '_onAddFollower',
         'click .o_add_follower_channel': '_onAddChannel',
@@ -286,7 +286,7 @@ var Followers = AbstractField.extend({
         // If no more subtype followed, unsubscribe the follower
         if (!checklist.length) {
             this._unfollow(ids).fail(function () {
-                $(event.target).prop('checked', true);
+                $(event.currentTarget).find('input').addBack('input').prop('checked', true);
             });
         } else {
             var kwargs = _.extend({}, ids);

addons/mail/static/src/scss/followers.scss

@@ -4,11 +4,6 @@
         display: none !important; // Hide the followers in mobile
     }
 
-    .dropdown-menu {
-        right: 0;
-        left: auto;
-    }
-
     .o_followers_actions {
         position: relative;
         float: right;

addons/mail/static/src/xml/followers.xml

@@ -12,7 +12,7 @@
                     <i class="fa fa-user" role="img" aria-label="Dropdown menu - Followers"></i>
                     <span class="o_followers_count"/>
                 </button>
-                <div class="dropdown-menu o_followers_list" role="menu"/>
+                <div class="dropdown-menu dropdown-menu-right o_followers_list" role="menu"/>
             </div>
             <div class="o_followers_actions">
                 <div class="btn-group o_subtypes_list">
@@ -25,7 +25,7 @@
                     </button><button class="btn btn-link dropdown-toggle" data-toggle="dropdown" aria-expanded="false">
                         <span class="fa fa-bell" role="img" aria-label="Alarm menu" title="Alarm menu"/>
                     </button>
-                    <div class="dropdown-menu" role="menu"/>
+                    <div class="dropdown-menu dropdown-menu-right" role="menu"/>
                 </div>
             </div>
         </div>