Setting a custom override_idle duration does not always work.

[krisgesling]

Describe the bug
Setting a custom override_idle duration does not always work.

Example is the Naptime Skill where we sleep for 5 seconds then release the GUI instead of override_idle=5. Some discussion here about that and the possible cause: MycroftAI/skill-naptime#41 (comment)

This may need to be addressed in the broader Skills interaction sprint

To Reproduce
Steps to reproduce the behavior:

1. show a page with override_idle=5
2. page does not always disappear after 5 seconds.

Expected behavior
should respect the duration of the override