Fix:failoverbug and retries change to string type

[hxmhlt]

What this PR does:
Fix:failoverbug and retries change to string type
Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[codecov-io]

Codecov Report

Merging #195 into develop will decrease coverage by 0.05%.
The diff coverage is 66.66%.

@@             Coverage Diff             @@
##           develop     #195      +/-   ##
===========================================
- Coverage    67.82%   67.76%   -0.06%     
===========================================
  Files           94       94              
  Lines         5862     5870       +8     
===========================================
+ Hits          3976     3978       +2     
- Misses        1474     1482       +8     
+ Partials       412      410       -2

Impacted Files	Coverage Δ
config/method_config.go	60% <ø> (ø)	⬆️
config/reference_config.go	82.75% <100%> (ø)	⬆️
config/service_config.go	65.82% <100%> (ø)	⬆️
cluster/cluster_impl/failback_cluster_invoker.go	78.49% <50%> (-0.63%)	⬇️
cluster/cluster_impl/failover_cluster_invoker.go	79.06% <62.5%> (-5.55%)	⬇️
config/base_config.go	60.81% <0%> (-2.71%)	⬇️
cluster/loadbalance/least_active.go	91.3% <0%> (ø)	⬆️
config_center/configuration_parser.go	50% <0%> (ø)	⬆️
filter/impl/active_filter.go	18.18% <0%> (ø)	⬆️
protocol/dubbo/pool.go	73.6% <0%> (+0.27%)	⬆️
... and 1 more

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[pantianying]

LGTM

[fangyincheng]

Modify config.yml of config/testdata/ pls.

[AlexStocks]

LGTM

[hxmhlt]

Modify config.yml of config/testdata/ pls.

done

[fangyincheng]

LGTM