Add global watch failure notification setting.

changedetectionio/forms.py

@@ -592,6 +592,7 @@ class globalSettingsApplicationForm(commonSettingsForm):
                                                                   render_kw={"style": "width: 5em;"},
                                                                   validators=[validators.NumberRange(min=0,
                                                                                                      message="Should contain zero or more attempts")])
+    notification_notify_on_failure = BooleanField('Send a notification on watch failure', default=False)
 
 
 class globalSettingsForm(Form):

changedetectionio/templates/settings.html

@@ -44,6 +44,9 @@
                         Set to <strong>0</strong> to disable
                         </span>
                     </div>
+                    <div class="pure-control-group">
+                        {{ render_checkbox_field(form.application.form.notification_notify_on_failure) }}
+                    </div>
                     <div class="pure-control-group">
                         {% if not hide_remove_pass %}
                             {% if current_user.is_authenticated %}