Fix error in run.py

run.py crashes for me right now because LinkResult.url is not set:
```
python run.py http://localhost:8888/blog/
FOR /blog/theme/static/common.css
Traceback (most recent call last):
  File "run.py", line 35, in <module>
    if link.href != link.url:
AttributeError: 'LinkResult' object has no attribute 'url'
```