Fix literal value passed as reactive property

[danxuliu]

[Vue warn]: Property or method "submit" is not defined on the instance but referenced during render. Make sure that this property is reactive, either in the data option, or for class-based components, by initializing the property. See: https://vuejs.org/v2/guide/reactivity.html#Declaring-Reactive-Properties.

found in

---> <LinkShareSettings> at src/components/ConversationSettings/LinkShareSettings.vue
       <AppSettingsSection>
         <Modal>
           <AppSettingsDialog>
             <ConversationSettingsDialog> at src/components/ConversationSettings/ConversationSettingsDialog.vue
               <Content>
                 <App> at src/App.vue
                   <Root>

[nickvergessen]

Already in #7711