fix auto escaping functionality of t()

Because of https://github.com/owncloud/core/pull/12687

Fully backwards compatible format. Once all supported platforms (that this version of the contacts app should run on) are using the autoescaping, this can be done via the build in auto escaping functionality of t().

cc @babelouest @jbtbnl

@LukasReschke @PVince81 @karlitschek Example of fully backwards compatible version for this change