Fix 411 Length Required on move_task API call

Google Tasks move endpoint requires Content-Length header
even on POST requests with no body.

src/infrastructure/api.rs

@@ -441,7 +441,11 @@ impl ApiClient {
             req = req.query(&[("destinationTaskList", s)]);
         }
 
-        let resp = req.send().await.map_err(|e| ApiError::Network(e.to_string()))?;
+        let resp = req
+            .header(reqwest::header::CONTENT_LENGTH, "0")
+            .send()
+            .await
+            .map_err(|e| ApiError::Network(e.to_string()))?;
 
         if !resp.status().is_success() {
             let status = resp.status();