Fix pgaccess __wish__ thing.

src/bin/pgaccess/pgaccess.sh

 #!/bin/sh
 
-PATH_TO_WISH=/usr/bin/wish
-PGACCESS_HOME=/usr/local/pgaccess
+PATH_TO_WISH=__wish__
+PGACCESS_HOME=__POSTGRESDIR__/pgaccess
 
 export PATH_TO_WISH
 export PGACCESS_HOME