Slovak translation update

[Dusan Kazik]

Hi.
I am Gnome translator and commiter(https://l10n.gnome.org/users/prescott/) and i a have updated slovak translation of simple scan to 100%.
I must share it this way, trough the bug report, because launchpad always freezes for me (webpage timeout) and translation are anyway not included in the trunk.

Please commit my translation from attachment.

Thank you very much and thanks for your great app!

[Dusan Kazik (prescott66)]

Please commit this translationfor branch 3.16. thank you.