fix: fix router_config add &url to url

[georgehao]

What this PR does:
fix bug
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 #910 (8f916e6) into develop (7efba16) will decrease coverage by 0.10%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop     #910      +/-   ##
===========================================
- Coverage    59.90%   59.79%   -0.11%     
===========================================
  Files          260      260              
  Lines        12854    12854              
===========================================
- Hits          7700     7686      -14     
- Misses        4191     4206      +15     
+ Partials       963      962       -1     

Impacted Files	Coverage Δ
config/router_config.go	68.18% <100.00%> (ø)
config_center/nacos/facade.go	79.31% <0.00%> (-10.35%)	⬇️
metadata/report/delegate/delegate_report.go	29.66% <0.00%> (-9.33%)	⬇️
config_center/nacos/client.go	65.26% <0.00%> (-2.11%)	⬇️
cluster/cluster_impl/failback_cluster_invoker.go	78.31% <0.00%> (+2.40%)	⬆️

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[zouyx]

Fix bug which is found in integration testing

https://github.com/apache/dubbo-go-samples/runs/1499794160?check_suite_focus=true