Read timeout causes attempt to recreate directory

[OJFord]

If a KBFS read operation times out, passbase takes it to mean the directory in which passwords are stored does not exist, and tries to recreate it, before crashing because it already exists.

Should check the nature of the file system read before attempting to create the dir.

> passbase read foo
# hangs
# Keybase pops up notifying that read timed out
Passbase directory does not exist in KBFS, creating...
thread 'main' panicked at 'Failed to create Passbase directory: Error { repr: Os { code: 17, message: "File exists" } }'