rename of force_parallel_mode

Many buildfarm members have something like this in their config (it's
part of the sample config that comes with the distribution):

    extra_config => {
       [...]
        HEAD => ['force_parallel_mode = regress'],
    },

This parameter has now been renamed in the git master (a.k.a. HEAD)
branch. See

<https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=5352ca22e0012d48055453ca9992a9515d811291>

The new name is debug_parallel_query. While the old name will work for a
while as an alias to the new name, we'd like to remove it. Please change
any configs you have to use the new name. If you are using it for any
branch other than HEAD, make sure that the change only applies to the
HEAD branch.

While this isn't urgent, I hope that most owners can make the change in
the next couple of weeks.

cheers

andrew

--
Andrew Dunstan
EDB:https://www.enterprisedb.com