Supported boolean values are now t, T, true, TRUE, f, F, false, and
FALSE. This is what the strconv.ParseBool function supports with
the exception of 1 and 0. 1 and 0 would be parsed as ints in the
line protocol.
Previously, any non-true value would be parsed as false. e.g.
value=blah would parse to false. This will now return an error as
parsing time.