[tx-robot] updated from transifex

apps/files/l10n/el.php

apps/files_encryption/l10n/el.php

apps/files_external/l10n/el.php

apps/files_external/l10n/sk_SK.php

apps/files_sharing/l10n/sk_SK.php

apps/user_ldap/l10n/el.php

core/l10n/el.php

l10n/el/core.po

l10n/el/files.po

l10n/el/files_encryption.po

l10n/el/files_external.po

l10n/el/lib.po

l10n/el/settings.po

l10n/el/user_ldap.po

l10n/sk_SK/core.po

l10n/sk_SK/files_external.po

l10n/sk_SK/files_sharing.po

l10n/sk_SK/lib.po

l10n/sk_SK/settings.po

l10n/templates/core.pot