Constant string `testOwnerID` for these tests has an invalid
format. It has 11 bytes instead of required 25 for `user.ID`.
It worked because:
1. `user.ID` was a byte slice and didn't check length
and format of byte slices decoded from strings.
2. in these tests `testOwnerID` was used only to decode
container owner id and to compare it with owner id encoded
back to string.
Since `user.ID implementation has changed`, the problem arised.
Now `testOwnerID` is valid.
Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>
