Do not allow the estimation of a parameter that appears in “planner_discount”

Ref. dynare#1173
6 jobs for master in 2 minutes and 30 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #14633
build_linux_32

00:00:43

passed #14634
build_linux_64

00:01:32

passed #14637
macOS
build_macOS

00:02:24

passed #14635
build_windows_32

00:01:36

passed #14636
build_windows_64

00:02:03

 
  Prepare
passed #14638
aggregate_builds

00:00:03