By switching to block style (`|`) with clip (no `-` or `+`) the failure
messages don't require quoting and gain a single trailing newline. This causes
Ansible to print them as block style, when using the yaml stdout callback
plugin. As a result the values have one less layer of quoting and quote
escaping, making them much easier to read.
This is the most minimal change for what might be relatively minimal
edge case. Alternative is replacing reload(), but let's not do that yet.
Closes#555
Alex Willmer