Treat empty string same as undefined
Treat empty string same as undefined

If an administrator clears the cert fingerprint, they will
likely set it to ''.  In such a case, go down the 'no fingerprint'
path rather than reject it.

whowutwut/confluent,jjohnson42/confluent,whowutwut/confluent,xcat2/confluent,xcat2/confluent,whowutwut/confluent,jjohnson42/confluent,xcat2/confluent,jjohnson42/confluent,jjohnson42/confluent,xcat2/confluent,jjohnson42/confluent,whowutwut/confluent,xcat2/confluent