levels: remove map19, many errors with boom
levels: remove map19, many errors with boom

Not actually removed, but the built IWAD will have a dummy level
in its place.

Signed-off-by: Mike Swanson <517655fde76fa2f07143b6c6f1774e4fae45930a@gmail.com>

CWolfRU/freedoom,jmtd/freedoom,jmtd/freedoom,jmtd/freedoom,CWolfRU/freedoom