Don't use select() in interactive python shell

Don't use select() in interactive python shell

This fixes the python interactive shell when running under
sel_ldr (in this case select() will always return ENOSYS
which python doesn't handle and we end up an infinite loop).

This wasn't a problem in the past since we didn't include
nacl_io on the link line, and hence python didn't compile
with select() support.

R=bradnelson@google.com

Committed: https://chromium.googlesource.com/external/naclports/+/4112c104e6737542b6c04430490d103495c3a7a8

[Sam Clegg, 2015-04-07 00:16:27]

sbc@chromium.org changed reviewers:
+ bradnelson@chromium.org

[Sam Clegg, 2015-04-07 00:17:43]

Found this while looking into a build for rabbithole.

[bradn, 2015-04-07 00:58:19]

bradnelson@google.com changed reviewers:
+ bradnelson@google.com

[bradn, 2015-04-07 00:58:20]

lgtm

[Sam Clegg, 2015-04-07 01:06:49]

Committed patchset #2 (id:20001) manually as
4112c104e6737542b6c04430490d103495c3a7a8 (presubmit successful).