Issue #275: Regression: Unicode comments fail to be posted (conservancy/kallithea)

[Konstantin Veretennicov]

New issue 275: Regression: Unicode comments fail to be posted
https://bitbucket.org/conservancy/kallithea/issues/275/regression-unicode-comments-fail-to-be

Konstantin Veretennicov:

Steps to reproduce:

1. Clean install Kallithea (on Windows, from sources, revision a1f8bf0)
2. Create 2 users
3. Create a repo and a PR
4. Post an inline comment with Unicode characters

Expected: comments to work as usual for all users.

Actual: only PR owner can post Unicode, for other users it fails.

There is an error in the server log:

```
  File "c:\kallithea\kallithea\lib\celerylib\tasks.py", line 307, in send_email
    % (' '.join(recipients), headers, subject, body, html_body))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd1 in position 150: ordinal not in range(128)
```