addressbook-query: Fix filter matching for empty filters

crates/carddav/src/addressbook/methods/report/addressbook_query/elements.rs

@@ -82,6 +82,11 @@ pub struct FilterElement {
 impl FilterElement {
     #[must_use]
     pub fn matches(&self, addr_object: &AddressObject) -> bool {
+        if self.prop_filter.is_empty() {
+            // Filter empty
+            return true;
+        }
+
         let Allof(allof) = self.test;
         let mut results = self
             .prop_filter

crates/carddav/src/addressbook/methods/report/addressbook_query/prop_filter.rs

@@ -32,6 +32,10 @@ pub struct PropFilterElement {
 impl PropFilterElement {
     #[must_use]
     pub fn match_property(&self, property: &Property) -> bool {
+        if self.param_filter.is_empty() && self.text_match.is_empty() {
+            // Filter empty
+            return true;
+        }
         let Allof(allof) = self.test;
         let text_matches = self
             .text_match