be explicit about expecting bytes from sock.recv

[mattbennett]

On Python3, callingeventlet.support.greendns._net_read will raise "TypeError: Can't convert 'bytes' object to str implicitly".

This happens when resolution is requested over TCP, or if resolution falls back to TCP when the UDP response is truncated (which is how we found it).

The bug was fixed in dnspython here.

[temoto]

Thanks, I want to have a test case on this.
If there's no test in reasonable time, LGTM from me, I'll merge or @jstasiak also has access.

[codecov-io]

Codecov Report

Merging #391 into master will not change coverage.
The diff coverage is 0%.

@@          Coverage Diff          @@
##           master   #391   +/-   ##
=====================================
  Coverage      54%    54%           
=====================================
  Files          79     79           
  Lines        9036   9036           
  Branches     1559   1559           
=====================================
  Hits         4889   4889           
  Misses       3826   3826           
  Partials      321    321

Impacted Files	Coverage Δ
eventlet/support/greendns.py	61% <ø> (ø)	✅
eventlet/hubs/hub.py	89% <ø> (-1%)	❌
eventlet/event.py	81% <ø> (+1%)	✅

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[gugu]

@temoto can you please merge it? There is no response from anyone, and greendns is buggy in python 3

[temoto]

Привет, Андрей. 👍

Fix is merged in master fa87d41

[gugu]

Спасибо!