ComposeBox: Don't save drafts of edited messages.

Author: WesleyAC

src/compose/ComposeBox.js

@@ -243,9 +243,11 @@ class ComposeBox extends PureComponent<Props, State> {
 
   handleMessageChange = (message: string) => {
     this.setState({ message, isMenuExpanded: false });
-    const { dispatch, narrow } = this.props;
+    const { dispatch, isEditing, narrow } = this.props;
     dispatch(sendTypingStart(narrow));
-    dispatch(draftUpdate(narrow, message));
+    if (!isEditing) {
+      dispatch(draftUpdate(narrow, message));
+    }
   };
 
   // See JSDoc on 'onAutocomplete' in 'AutocompleteView.js'.