Support more notification recipients (MID-4534)

When recipient expression was used, the number of recipients
was limited to 1. Thanking Michael for the fix.

model/notifications-impl/src/main/java/com/evolveum/midpoint/notifications/impl/handlers/BaseHandler.java

@@ -181,6 +181,7 @@ private List<String> evaluateExpression(ExpressionType expressionType, Expressio
 
         QName resultName = new QName(SchemaConstants.NS_C, "result");
         PrismPropertyDefinition<String> resultDef = new PrismPropertyDefinitionImpl<>(resultName, DOMUtil.XSD_STRING, prismContext);
+        resultDef.setMaxOccurs(-1);
 
         Expression<PrismPropertyValue<String>,PrismPropertyDefinition<String>> expression = expressionFactory.makeExpression(expressionType, resultDef, shortDesc, task, result);
         ExpressionEvaluationContext params = new ExpressionEvaluationContext(null, expressionVariables, shortDesc, task, result);