import tool: fix bug importing demo csv

[chrisnoisel]

I noticed the demo CSV file supplied with the import tool did not work so i made some modifications :

• no more redundant storage error message
• last view (show_imported_parts) is now displayed
• removed auto refresh JS putting the browser in an infinite loop

[jbtronics]

Your pull request seems to work fine. Thank you for your fix.

Sorry for my long response time, I was mostly working on the new Part-DB version and forgot about your pull request.