dot/profile: Reduce the default ulimit a smidge.

dot/profile: Reduce the default ulimit a smidge.

The dash(1) shell has an awful bug on 32-bit systems.  Although the
limit is presented to the shell as a number of kilobytes, it's presented
to the setrlimit(2) syscall as a number of /bytes/.  It seems that
dash(1) performs this calculation using 32-bit integers on 32-bit
platforms, and, with the chosen default of 4194304, ends up with zero,
and nothing can start up.

Reduce the limit by a kilobyte to avoid frying dash(1)'s brain.