Regenerate "discouraged" per recent changes
Regenerate "discouraged" per recent changes

  Fix "discouraged" file, which has to be changed to pass the CI tests
  on Travis to meet the recent changes.

  The "discouraged" file was regenerated by this command:
  metamath 'read set.mm' 'set width 9999' 'show discouraged' quit |
  grep '^SHOW DISCOURAGED.' | sed -E -e 's/^SHOW DISCOURAGED.  ?//' |
  LC_ALL=C sort > discouraged

metamath/set.mm,metamath/set.mm,metamath/set.mm