update created time

[NameHaibinZhang]

update created time for connection reuse

[CLAassistant]

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[codecov-io]

Codecov Report

Merging #54 into develop will increase coverage by 0.13%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop      #54      +/-   ##
===========================================
+ Coverage    67.04%   67.17%   +0.13%     
===========================================
  Files           46       46              
  Lines         3295     3296       +1     
===========================================
+ Hits          2209     2214       +5     
+ Misses         850      846       -4     
  Partials       236      236

Impacted Files	Coverage Δ
protocol/dubbo/pool.go	69.72% <100%> (+0.16%)	⬆️
protocol/dubbo/listener.go	49.18% <0%> (-2.74%)	⬇️
cluster/cluster_impl/base_cluster_invoker.go	68.08% <0%> (+19.14%)	⬆️

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