Revert "capsicum: allow terminal events"
Revert "capsicum: allow terminal events"

This reverts commit 7090ef09fbcec2c50ba15ddebb2c18cf3eda8377.

fstat/ioctl are checking whether the program is attached to tty for
setting buffering. Since xmppipe explicitly enables line buffering, the
capsicum sandbox can ignore these tests.

msantos/xmppipe,msantos/xmppipe