code in parse_conf_file() to trim trailing blanks/cr was missing them

code in parse_conf_file() to trim trailing blanks/cr was missing them

Observed on a text file with crlf endings on Linux, where the
so-called blank lines weren't being ignored as they should
have been, despite there being a line to remove \r from the
end.

A pointer was being pre-decremented before the check for a
matching whitespace character.