remove unused and strange default-value for pins

remove unused and strange default-value for pins

If the pin for a generic pin is 0, it get a value by strange looking
rules, if the pin is specific the rules are at least not strange, but
the value 989 is a magic number without any direct meaning… but both
never happens in practice as the parsing skips such entries with a
warning, so there always is a priority != 0 and the code therefore never
used.