l10n: updated Greek (el)
l10n: updated Greek (el)

contributors:
  Adrian
  Dimitris Maroulidis

updated from:
  repo: https://github.com/freedomofpress/securedrop-i18n
  revision: 28f8f89d96b061345a95a3d7f4ddd10c9bf2c173

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