fix logic introduced in addNewAccountInternal

Jenkins' PHP codesniffer complains about the whitespace at line 318.
I'm pretty sure gerrit 17952 (commit 69ea4400) introduced bad logic.
Part of the if statement boils down to
    userExists( userName ||  authenticate( userName, password) )
if userName is falsy then it calls userExists on the boolean return
value of authenticate().  I think this change puts it back to the way it
was.

Change-Id: If334464ffa993490abe8919591a18a4c3935bcfb
Merge "fix logic introduced in addNewAccountInternal"