[TD-524] fix python connector

src/connector/python/linux/python2/taos/cinterface.py

@@ -150,6 +150,7 @@ class CTaosInterface(object):
     libtaos.taos_fetch_lengths.restype = ctypes.c_void_p
     libtaos.taos_free_result.restype = None
     libtaos.taos_errno.restype = ctypes.c_int
+    libtaos.taos_query.restype = ctypes.POINTER(ctypes.c_void_p)
 
     def __init__(self, config=None):
         '''

src/connector/python/windows/python2/taos/cinterface.py

@@ -150,6 +150,7 @@ class CTaosInterface(object):
     libtaos.taos_fetch_lengths.restype = ctypes.c_void_p
     libtaos.taos_free_result.restype = None
     libtaos.taos_errno.restype = ctypes.c_int
+    libtaos.taos_query.restype = ctypes.POINTER(ctypes.c_void_p)
 
     def __init__(self, config=None):
         '''

src/connector/python/windows/python3/taos/cinterface.py

@@ -150,6 +150,7 @@ class CTaosInterface(object):
     libtaos.taos_fetch_lengths.restype = ctypes.c_void_p
     libtaos.taos_free_result.restype = None
     libtaos.taos_errno.restype = ctypes.c_int
+    libtaos.taos_query.restype = ctypes.POINTER(ctypes.c_void_p)
 
     def __init__(self, config=None):
         '''