patchbomb: use single quotes around command hint
Windows command lines use double quotes to quote arguments with spaces.
This change is in a series to unify around using single quotes around
commands, and double quotes around interior arguments.
This changeset is taken on stable for consistency with similar update done
before the freeze.
See
2e58dc022caa,
ad2cd2ef25d9,
fc1d75e7a98d and
9dcc9ed26d33.