Before this change, on the first attempt to create a backend we used a
non-canonicalized string. When the backend expired the second attempt
to create it would use the canonicalized string (because it was in the
remap cache) which would fail because it was now `name{XXXX}:`
This change makes sure that whenever we create a backend we always use
the non-canonicalized string.
See: https://forum.rclone.org/t/connection-string-inconsistencies-on-beta/23171
d0f8b4f479