Remove (useless) s/*/__star__/ replacement in getconf.

It seems this was meant to replace * with __star__ to prevent globbing,
but getconf already handles its values properly so globbing does not
occur. Currently, this replacement was broken due to the double
backslash, causing it to replace a backslash and all following
characters with __star__, instead of a literal *. This is also confirmed
by the fact that some handlers' documentation says to use __star__
instead of * directly in the configuration (and they have special
handling to turn __star__ back into * or something else as appropriate).

Eventually, we should just support using * directly and fixing up all
handling of the variable to not cause any globbing or other expansion
(also because fixing * isn't complete, there is also ? and sometimes ~
and other special characters might be expanded as well).