FR#5768_21 Magento 2.0.7 XML sitemap is not generated by schedule [Backport 2.1 develop]

[mrodespin]

Magento 2 sitemap generation frequency configuration was not working. When a administrator wants to enable the functionality of automatic sitemap generation the frequency was not saving in cron_schedule table.

Description

The commit solves the issue on saving magento 2 automatic sitemap generation configuration. With these modifications the cron job is working properly.

Manual testing scenarios

1. go to admin>store>configurtion>catalog>xml sitemap
2. turn on generation and set up time.
3. Execute php bin/magento cron:run
4. Go to cron_schedule table and the cron job sitemap_generate is not in the table

With this modification if we do the same process the cron job appears in the table (If the time configured is nearby)

Related PRs:

#11474

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[dmanners]

This is the same as #11475 the change does not fix an issue but is only changing of code styles.