fix [#35154] Python: UI issues with invoke_props_dialog()
- highlighed buttons that were never pressed could be activated by accident when canceling search popup. 
- canceling a search popup on a popup would close both.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56399 954f8c5b-7b00-dc11-b283-0030488c597c