some codes have SyntaxError in python high version

Syntax location: HttpLibrary/__init__.py :row 16,551

```python
except ValueError, e:
```

It should be like this in high version of python:

```python
expect ValueError as e:
```

If it wants to be compatible with low version, please add a `if(sys.version_info.major>3&&sys.version_info.minor<7)`to  select which usage.