Upgrade apollo-client to 1.3.0 version & Add to unsubscribe config change event

[HaojunRen]

Add to unsubscribe config change event for new apollo-client version.

Fixes #561

[CLAassistant]

All committers have signed the CLA.

[codecov-io]

Codecov Report

Merging #562 into master will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #562      +/-   ##
============================================
- Coverage      38.8%   38.79%   -0.02%     
+ Complexity     1171     1170       -1     
============================================
  Files           267      267              
  Lines          8414     8414              
  Branches       1133     1133              
============================================
- Hits           3265     3264       -1     
  Misses         4726     4726              
- Partials        423      424       +1

Impacted Files	Coverage Δ	Complexity Δ
...l/cluster/server/connection/ConnectionManager.java	74% <0%> (-2%)	10% <0%> (-1%)

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[sczyh30]

Hi, could you please sign the CLA here: https://cla-assistant.io/alibaba/Sentinel?pullRequest=562

[sczyh30]

LGTM

[sczyh30]

Thanks for contributing!