[tx-robot] updated from transifex

apps/accessibility/l10n/ar.js

apps/accessibility/l10n/ar.json

apps/accessibility/l10n/ru.js

apps/accessibility/l10n/ru.json

apps/comments/l10n/sr.js

apps/comments/l10n/sr.json

apps/dav/l10n/sr.js

apps/dav/l10n/sr.json

apps/federatedfilesharing/l10n/sr.js

apps/federatedfilesharing/l10n/sr.json

apps/files_external/l10n/sr.js

apps/files_external/l10n/sr.json

apps/settings/l10n/el.js

apps/settings/l10n/el.json

apps/settings/l10n/sr.js

apps/settings/l10n/sr.json

apps/sharebymail/l10n/sr.js

apps/sharebymail/l10n/sr.json

core/l10n/sr.js

core/l10n/sr.json