Activate propfind propname, was already implemented :D

crates/dav/src/methods/propfind.rs

@@ -66,8 +66,7 @@ pub async fn route_propfind<R: ResourceService>(
             vec!["allprop".to_owned()]
         }
         PropfindType::Propname => {
-            // TODO: Implement
-            return Err(Error::InternalError.into());
+            vec!["propname".to_owned()]
         }
         PropfindType::Prop(PropElement { prop: prop_tags }) => prop_tags.into_inner(),
     };