[tx-robot] updated from transifex

apps/files/l10n/de.php

apps/files/l10n/de_DE.php

apps/files/l10n/th_TH.php

core/l10n/ca.php

core/l10n/cs_CZ.php

core/l10n/de_DE.php

core/l10n/el.php

core/l10n/fi_FI.php

core/l10n/it.php

core/l10n/ja_JP.php

core/l10n/si_LK.php

core/l10n/sk_SK.php

core/l10n/th_TH.php

core/l10n/zh_CN.php

l10n/ar/core.po

l10n/bg_BG/core.po

l10n/ca/core.po

l10n/cs_CZ/core.po

l10n/da/core.po

l10n/de/core.po