Backport fix for OPENDJ-1252: ReadSchema example throws NPE

Matthew Swift

13.40.2013 249f365384d6e9927fc8cd3e161a789bbaf0ed47

 opendj-ldap-sdk/src/main/java/org/forgerock/opendj/ldap/schema/Syntax.java

@@ -318,7 +318,12 @@
            }

            if (impl == null) {
                impl = schema.getDefaultSyntax().impl;
                final Syntax defaultSyntax = schema.getDefaultSyntax();
                if (defaultSyntax.impl == null) {
                    // The default syntax was never validated.
                    defaultSyntax.validate(schema, warnings);
                }
                impl = defaultSyntax.impl;
                final LocalizableMessage message = WARN_ATTR_SYNTAX_NOT_IMPLEMENTED1
                        .get(getDescription(), oid, schema.getDefaultSyntax()
                                .getOID());