4.2 telnetd AYT bug

[rws%mit-bold at sri-unix.UUCP]

From:  Robert W. Scheifler <rws at mit-bold>

Description:
	When the telnet daemon receive an Are You There, it writes a ^G
	to the pty rather than back to the network.
Repeat-By:
	Telnet to a 4.2 host with a user telnet that can send AYT's, and
	send one.  See the ^G echo and show up in your input buffer, rather
	than ringing your bell.
Fix:
	Change
			case AYT:
				*pfrontp++ = BELL;
				break;
	to
			case AYT:
				*nfrontp++ = BELL;
				break;