Remove unwrap_str_err method from UnwrapError test trait

With upcoming changes we intend to move towards a model where we do not
distinguish the individual error variants the program deals with in a
global enum.
In preparation of such a change, this patch marks a first step in
removing the UnwrapError test trait, which relies on the existence of
exactly such typed errors. In particular, we remove the unwrap_str_err
method from it, basically falling back to just working with strings.

0 files changed, 0 insertions, 0 deletions