Remove the blocker div on start of navigation
Fixed set_pxe_image_type

* When running multiple tests, the image may already have been set in
  which case the buttons failed to become active.
Merge pull request #934 from mfalesni/blocker

Remove the blocker div on start of navigation
Merge pull request #935 from psav/set_pxe_image_fix

Fixed set_pxe_image_type