Can't start ES 7.3.0 with x-pack security enabled

[TimV (Tim Vernum)]

@ikakavas

If you want/need to use a password protected keystore/truststore, then you need to set also

xpack.security.transport.ssl.keystore.password: 
xpack.security.transport.ssl.truststore.password: 

This should not be necessary. We assume that the password is blank if it is not specified. Simply create a PKCS#12 file with a blank password, and leave the .password (and .secure_password) unset.