Allow initdb to complete on systems without "locale" command
This partially reverts
2fe3bdbd691a5d11626308e7d660440be6c210c8, which
added an error check on the "locale -a" execution. This is removed
again, adding a comment explaining why. We already had code that
shows a warning if no system locales could be found, which should be
sufficient for feedback to the user.
Discussion: https://www.postgresql.org/message-id/flat/
b2b491d1-3b36-15b9-6910-
5b5540b27f5c%40enterprisedb.com