Add a check for empty params for url join (#9356)

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Fix for #9347 

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- [x] Add unit tests
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crates/nu-command/src/network/url/join.rs

@@ -191,7 +191,11 @@ impl UrlComponents {
                         .collect::<Result<Vec<String>, ShellError>>()?
                         .join("&");
 
-                    qs = format!("?{qs}");
+                    qs = if !qs.trim().is_empty() {
+                        format!("?{qs}")
+                    } else {
+                        qs
+                    };
 
                     if let Some(q) = self.query {
                         if q != qs {

crates/nu-command/tests/commands/url/join.rs

@@ -366,3 +366,21 @@ fn url_join_with_fragment_and_params() {
         "http://usr:pwd@localhost:1234?par_1=aaa&par_2=bbb#frag"
     );
 }
+
+#[test]
+fn url_join_with_empty_params() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+            r#"
+            {
+                "scheme": "https",
+                "host": "localhost",
+                "path": "/foo",
+                "params": {}
+            } | url join
+            "#
+        )
+    );
+
+    assert_eq!(actual.out, "https://localhost/foo");
+}