The java.security.krb5.realm system property only needs to be defined once

There are 3 {@systemProperty java.security.krb5.realm} in src/java.security.jgss/share/classes/javax/security/auth/kerberos/KerberosPrincipal.java and src/java.security.jgss/share/classes/javax/security/auth/kerberos/package-info.java. There should only be one. See https://mail.openjdk.java.net/pipermail/core-libs-dev/2018-November/056653.html.