At some point between 0.9.9 and 0.9.10 we removed the printing of option
names when a value doesn't have a default, but this means the config is
littered with things like:
# This option sets the greater foo value.
with no actual option name printed out when there is no default.
This fixes it by always printing the option name in such a case, just
with an empty value, e.g.:
# This option sets the greater foo value.
#big-foo=