In verify_sdp.sh, made check for SDP password file a skippable check.
This also skips the check for SDP_ADMIN_PASSWORD_FILE variable.
=== WARNING DO NOT SUBMIT! ===
I think this should not be implemented, at least not by itself. The SDP
doesn't currently support not having a password file. Without
a password file, the p4login script (called by many other SDP scripts)
will not function. There may be a good reason to have SDP not require a
password cleartext password file, but doing so may require extensive
See: SDP-641: Get SDP to work without a cleartext password file.