[9.20] chg: usr: allow shorter resolver-query-timeout configuration

The minimum allowed value of 'resolver-query-timeout' was lowered to
301 milliseconds instead of the earlier 10000 milliseconds (which is the
default). As earlier, values less than or equal to 300 are converted to
seconds before applying the limit.

Closes #4320

Backport of MR !9091

Merge branch 'backport-4320-allow-shorter-resolver-query-timeout-configuration-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!9220