e1m7: fix player starts
e1m7: fix player starts

It had two Player 3 starts and no Player 4 start.  Corrected to have
all co-op starts now.

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

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