fix: panic when empty question qname;

Cargo.lock

@@ -1075,7 +1075,7 @@ dependencies = [
 
 [[package]]
 name = "pkdns"
-version = "0.2.1"
+version = "0.2.2"
 dependencies = [
  "any-dns",
  "chrono",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pkdns"
-version = "0.2.1"
+version = "0.2.2"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

src/pkarr_resolver.rs

@@ -83,6 +83,9 @@ impl PkarrResolver {
         }
         let question = question_opt.unwrap();
         let labels = question.qname.get_labels();
+        if labels.len() == 0 {
+            return Err("No label in question.qname.".into());
+        };
 
         let raw_pubkey = labels.last().unwrap().to_string();
         let parsed_option = Self::parse_pkarr_uri(&raw_pubkey);