Remove listener when NetworkError is catched

[jenow]

What does this PR do?

Remove listener on NetworkError once we catched it before reconnecting, otherwise we will write in it but nothing will be listening to it and this will block the whole process of Connect

[codecov]

Codecov Report

Merging #251 into master will decrease coverage by 0.06%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #251      +/-   ##
==========================================
- Coverage   88.91%   88.85%   -0.07%     
==========================================
  Files         244      244              
  Lines        4466     4467       +1     
==========================================
- Hits         3971     3969       -2     
- Misses        441      444       +3     
  Partials       54       54

Impacted Files	Coverage Δ
kuzzle/kuzzle.go	27.65% <0%> (-0.2%)	⬇️
realtime/subscribe.go	70.58% <0%> (-5.89%)	⬇️

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[codecov]

Codecov Report

Merging #251 into master will decrease coverage by 0.04%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #251      +/-   ##
==========================================
- Coverage   88.91%   88.87%   -0.05%     
==========================================
  Files         244      244              
  Lines        4466     4466              
==========================================
- Hits         3971     3969       -2     
- Misses        441      443       +2     
  Partials       54       54

Impacted Files	Coverage Δ
kuzzle/kuzzle.go	27.85% <0%> (ø)	⬆️
realtime/subscribe.go	70.58% <0%> (-5.89%)	⬇️

---

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 df484a7...529b4a1. Read the comment docs.