Add missing trailing comma

Author: tvdijen

src/XML/md/SPSSODescriptor.php

@@ -107,7 +107,7 @@ function (AttributeConsumingService $acs) {
                 },
             ),
             1,
-            'Only one md:AttributeConsumingService can be set as default.',
+            'At most one <AttributeConsumingService> element can have the attribute isDefault set to true.',
         );
     }
 

tests/SAML2/XML/md/SPSSODescriptorTest.php

@@ -287,7 +287,7 @@ public function testUnmarshallingTwoDefaultACS(): void
 
         $this->expectException(AssertionFailedException::class);
         $this->expectExceptionMessage(
-            'At most one <AttributeConsumingService> element can have the attribute isDefault set to true.'
+            'At most one <AttributeConsumingService> element can have the attribute isDefault set to true.',
         );
 
         SPSSODescriptor::fromXML($xmlRepresentation->documentElement);