[FIX] mail_show_follower: More models to exclude

Slides and forums are also places where you don't want to show the recipients.

mail_show_follower/data/config_parameter_data.xml

@@ -2,6 +2,8 @@
 <odoo noupdate="1">
     <record id="models_to_exclude_config_parameter" model="ir.config_parameter">
         <field name="key">show_followers.models_to_exclude</field>
-        <field name="value">blog.blog,blog.post</field>
+        <field
+            name="value"
+        >blog.blog,blog.post,slide.slide,slide.channel,forum.forum,forum.post</field>
     </record>
 </odoo>