Merge branch 'jc/undefined-in-rte-fix' into 'master'

Handle undefined body and html for rte

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/184140



Merged-by: Deepika Guliani <dguliani@gitlab.com>
Approved-by: Deepika Guliani <dguliani@gitlab.com>
Approved-by: Nick Leonard <nleonard@gitlab.com>
Reviewed-by: Nick Leonard <nleonard@gitlab.com>
Co-authored-by: Jack Chapman <jachapman@gitlab.com>

app/assets/javascripts/vue_shared/components/markdown/markdown_editor.vue

@@ -265,7 +265,7 @@ export default {
       return axios
         .post(url, { text: markdown })
         .then(({ data: { html, body, ...otherData } = {} } = {}) => ({
-          body: body || html,
+          body: body || html || '',
           ...otherData,
         }));
     },