Use intervalStart() in b.e.autoresponder.createResponseBody().

 * CHANGE `bridgedb.email.autoresponder.getResponseBody()` to use
   `bridgedb.schedule.intervalStart()`, not `getInterval()`.

Signed-off-by: Isis Lovecruft <isis@torproject.org>
These were part of the hotfixes to ponticum on 2014-07-16.
Fix utf-8 encoding errors in email.autoresponder module.

 * FIXES several write errors due to encoding issues on production
   server.

Signed-off-by: Isis Lovecruft <isis@torproject.org>
These were part of the hotfixes to ponticum on 2014-07-16.
Fix an additional utf-8 encoding error for optional email headers.
Revert check for SMTP/email header canonical hostname equivalence.

Signed-off-by: Isis Lovecruft <isis@torproject.org>

For now, we need to revert this check to get the email distributor to
function. We should look into this issue in order to get BridgeDB in a
state where instances of it are runnable by other organisations to hand
out their own bridges. [OTHER_ORG]

Fixing this is essential for #12086.
Merge branch 'fix/12627-hotfixes' into develop