l10n: updated Slovak (sk)
l10n: updated Slovak (sk)

contributors:
  1000101
  ViktoriaAndr

updated from:
  repo: https://github.com/freedomofpress/securedrop-i18n
  commit: 2e52ab4e092554d1244fac75be3aea51eb881717

conorsch/securedrop,conorsch/securedrop,conorsch/securedrop,conorsch/securedrop,conorsch/securedrop