Setting path to existing file as quickstart examples installation target doesn't unpack them although no error dialogue appear.

reproduce
- create an empty file (e.g. /home/pkremens/test)
- choose "Install quickstarts" from Configure runtime environment options
- set the quickstarts installation target so it points to the empty file (/home/pkremens/test)
- finish the installation

actual

...
Unpacking complete.
Installing Quickstarts
Quickstart Installation Finished
...

during installation procedure, although qs examples are not installed

expected
User should be warned that qs examples installation target cannot point to an existing file. How about some error dialogue here?