update upload

serve/upload.py

@@ -12,7 +12,7 @@ ssh_client = None
 sftp_client = None
 sftp_client_imgs = None
 
-def open_sftp():
+def open_sftp(i=0):
     global ssh_client
     sftp_client = ssh_client.open_sftp()
     return sftp_client
@@ -28,7 +28,7 @@ def create_ssh_client(server, port, user, password):
     transport.set_keepalive(60)
 
     with concurrent.futures.ThreadPoolExecutor() as executor:
-        futures = [executor.submit(ssh_client) for _ in range(5)]
+        futures = [executor.submit(open_sftp, i) for i in range(5)]
         results = [future.result() for future in futures]
 
     sftp_client = results[0]