backup: avoid Transport endpoint is not connected error

We simply supress the error message if the finish flag is set.

src/api2/backup.rs

@@ -182,8 +182,22 @@ async move {
                 http.http2_initial_connection_window_size(window_size);
                 http.http2_max_frame_size(4*1024*1024);
 
+                let env3 = env2.clone();
                 http.serve_connection(conn, service)
-                    .map_err(Error::from)
+                    .map(move |result| {
+                        match result {
+                            Err(err) => {
+                                // Avoid  Transport endpoint is not connected (os error 107)
+                                // fixme: find a better way to test for that error
+                                if err.to_string().starts_with("connection error") && env3.finished() {
+                                    Ok(())
+                                } else {
+                                    Err(Error::from(err))
+                                }
+                            }
+                            Ok(()) => Ok(()),
+                        }
+                    })
             });
         let mut abort_future = abort_future
             .map(|_| Err(format_err!("task aborted")));

src/api2/backup/environment.rs

@@ -567,6 +567,12 @@ impl BackupEnvironment {
         Ok(())
     }
 
+    /// Return true if the finished flag is set
+    pub fn finished(&self) -> bool {
+        let state = self.state.lock().unwrap();
+        state.finished
+    }
+
     /// Remove complete backup
     pub fn remove_backup(&self) -> Result<(), Error> {
         let mut state = self.state.lock().unwrap();