Fixed ConnectionsPool.[pubsub_channels/pubsub_patterns]

[frostoov]

Fixed bug in commands.pubsub.PubSubCommandsMixin.subscribe (and psubscribe). ConnectionsPool.pubsub_channles code was called before ConnectionsPool._pubsub_conn creation, and therefore pubsub_channles

[codecov]

Codecov Report

Merging #351 into master will decrease coverage by 0.02%.
The diff coverage is 80%.

@@            Coverage Diff             @@
##           master     #351      +/-   ##
==========================================
- Coverage   96.86%   96.84%   -0.03%     
==========================================
  Files          54       54              
  Lines        7309     7319      +10     
  Branches      519      519              
==========================================
+ Hits         7080     7088       +8     
- Misses        168      169       +1     
- Partials       61       62       +1

Impacted Files	Coverage Δ
aioredis/util.py	94.07% <80%> (-1.13%)	⬇️
tests/sentinel_failover_test.py	86.46% <0%> (-1.51%)	⬇️
aioredis/sentinel/pool.py	80.22% <0%> (+0.76%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5f44b2a...ea6d5da. Read the comment docs.

[popravich]

Thanks for the report.
I've pushed a bit simpler patch.