#219 No return link in error message pages

[Niklas Vainio]

Webmin 0.90.

An example:
When user is creating new master zone with BIND
module and enters invalid data in the fields and then
presses Create, Webmin gives an error page. This page
doesn't include a link to get back to Create Master
Zone page. User can get there only with Back-button
of his or her browser.

This goes also for other modules, at least Apache.

This is a minor, non-critical usability issue.