Don't set initial password.

Setting the initial password on new accounts to '' was broken behaviour
introduced by 96fc5ae69bc0d1c0037e2223f0dccfcf6347abed.

Don't set userPassword field, this should result in a account
with no usable password.

Change-Id: I98bfaeebf39789e2a45dd177086fef7b8ecb78f4