Revert r1.33

Per RFC-5198:
   2.  In Net-ASCII, CR MUST NOT appear except when immediately followed
       by either NUL or LF, with the latter (CR LF) designating the "new
       line" function.  Today and as specified above, CR should
       generally appear only when followed by LF.  Because page layout
       is better done in other ways, because NUL has a special
       interpretation in some programming languages, and to avoid other
       types of confusion, CR NUL should preferably be avoided as
       specified above.

It's not worth breaking all connections for some broken telnet servers.
Especially since we do not explicitly want CR behaviour which is the only
place it's allowed.

Per RFC-854:
   the sequence "CR NUL" must be used where a carriage return alone is
   actually desired;

It's quite possible that these "telnet servers" are actually raw socket
servers and should use raw sockets rather than telnet.