[fix] add parameter hardware_version in get_vacuum_gripper

Author: vimior

doc/api/xarm_api.md

@@ -1664,10 +1664,13 @@ xArm-Python-SDK API Documentation (V1.14.6): class XArmAPI in module xarm.wrappe
 >         6: save failed
 
 
-#### def __get_vacuum_gripper__(self):
+#### def __get_vacuum_gripper__(self, hardware_version=1):
 
 > Get vacuum gripper state  
 >   
+> :param hardware_version: hardware version  
+>     1: Plug-in Connection, default  
+>     2: Contact Connection  
 > :return: tuple((code, state)), only when code is 0, the returned result is correct.  
 >     code: See the [API Code Documentation](./xarm_api_code.md#api-code) for details.  
 >     state: suction cup state  

xarm/wrapper/xarm_api.py

@@ -1913,17 +1913,20 @@ def get_tgpio_analog(self, ionum=None):
         """
         return self._arm.get_tgpio_analog(ionum)
 
-    def get_vacuum_gripper(self):
+    def get_vacuum_gripper(self, hardware_version=1):
         """
         Get vacuum gripper state
 
+        :param hardware_version: hardware version
+            1: Plug-in Connection, default
+            2: Contact Connection
         :return: tuple((code, state)), only when code is 0, the returned result is correct.
             code: See the [API Code Documentation](./xarm_api_code.md#api-code) for details.
             state: suction cup state
                 0: suction cup is off
                 1: suction cup is on
         """
-        return self._arm.get_suction_cup()
+        return self._arm.get_suction_cup(hardware_version=hardware_version)
 
     def set_vacuum_gripper(self, on, wait=False, timeout=3, delay_sec=None, sync=True, hardware_version=1):
         """