fix(tasks.extract_from_html): Catch UnicodeDecodeError

[grossir]

UnicodeDecodeError was bubbling because except clause was not catching it

Solves #181

[flooie]

@mlissner - sorry to get in the way of this.

[mlissner]

We passed like ships in the night! My thought was that if we want to remove it — you tell me — I could do it and then we'd know if my magic powers fix the deployment workflow.

[flooie]

I say let it disappear into the ether.

[mlissner]

Hm, there's something interesting (clever?) going on here:

https://github.com/freelawproject/doctor/blob/adf391227995a1360d673f07258e9ce1af5f51e4/doctor/lib/utils.py#L93-L95

Hm...I don't have time to think through if we want to remove that or if it's doing something useful, but happy to do what you say.