Fix multi-predicate support in the hoksso ruleset

From commit hash ukf/ukf-testbed/eaed41d716787ea25d914d7101a9e5baed7c570c

See ukf/ukf-meta#416 for details

mdx/_rules/check_hoksso.xsl

@@ -55,7 +55,7 @@
         or on md:AssertionConsumerService.
     -->
     <xsl:template match="@hoksso:ProtocolBinding
-        [not(parent::md:SingleSignOnService)][not(parent::md:AssertionConsumerService)]">
+        [not(parent::md:SingleSignOnService or parent::md:AssertionConsumerService)]">
         <xsl:call-template name="error">
             <xsl:with-param name="m">
                 <xsl:text>hoksso:ProtocolBinding may not appear on </xsl:text>