fix(core): RMC boolean value fix (n8n-io#6397)

Author: michael-radency

packages/editor-ui/src/components/ResourceMapper/MappingFields.vue

@@ -189,7 +189,13 @@ function getFieldDescription(field: ResourceMapperField): string {
 function getParameterValue(parameterName: string): string | number | boolean | null {
 	const fieldName = parseResourceMapperFieldName(parameterName);
 	if (fieldName && props.paramValue.value) {
-		return props.paramValue.value[fieldName] || '';
+		if (
+			props.paramValue.value[fieldName] === undefined ||
+			props.paramValue.value[fieldName] === null
+		) {
+			return '';
+		}
+		return props.paramValue.value[fieldName];
 	}
 	return null;
 }