title: importing address book in roundcube doesn't do anything
body: <p>I implemented roundcube mail as a mail manager on a virtual private server of mine.
  Everything works fine, but the address book import utility.
  After extracting the CSV file from my desktop pc address book, I follow the instruction to import contacts:
  address book, import, browse, import button.
  The procedure works until "browse". 
  When I press the import button, it reloads the import page and no contact has been imported.
  do you have any experience about that? 
  Am I missing anything in the roundcube config? Maybe a tmp folder where to upload csv, vcf files? Permissions?
  I have checkd and I have a tmp folder in the root of roundcube, set to 777.
  Users of my server are getting frustrated and really don't know what's not working.
  Thank for your preciuos help.</p>