fix props deserialization (quick-xml doesn't support untagged enums)

crates/carddav/src/addressbook/resource.rs

@@ -66,11 +66,11 @@ pub enum AddressbookProp {
     // Didn't find the spec
     Getctag(String),
 
-    #[serde(skip_deserializing, untagged)]
+    #[serde(skip_deserializing, rename = "$value")]
     #[from]
     ExtCommonProperties(CommonPropertiesProp),
 
-    #[serde(untagged)]
+    #[serde(other)]
     #[default]
     Invalid,
 }