feat(log): log load config only when Debug level

[Cluas]

Description (what this PR does / why we need it):

Normally we don't need to know the config load key info, only we need to be aware of it when debugging.
So change Info level to Debug

Which issue(s) this PR fixes (resolves / be part of):

fixes #

Other special notes for reviewer:

[Cluas]

It looks like there is a problem with some tests, can you help look at them? @huyuanxin

[huyuanxin]

It looks like there is a problem with some tests, can you help look at them? @huyuanxin

ok, I will fix docker image

update:
Now, docker image is fixed, please try run test actions again @Cluas

[Cluas]

It looks like there is a problem with some tests, can you help look at them? @huyuanxin

ok, I will fix docker image

update: Now, docker image is fixed, please try run test actions again @Cluas

Thanks

[codecov-commenter]

Codecov Report

Merging #1899 (8d8f644) into main (e66a290) will increase coverage by 0.01%.
The diff coverage is 87.50%.

❗ Current head 8d8f644 differs from pull request most recent head 69948aa. Consider uploading reports for the commit 69948aa to get more accurate results

@@            Coverage Diff             @@
##             main    #1899      +/-   ##
==========================================
+ Coverage   80.80%   80.81%   +0.01%     
==========================================
  Files          80       80              
  Lines        3568     3565       -3     
==========================================
- Hits         2883     2881       -2     
+ Misses        478      477       -1     
  Partials      207      207              

Impacted Files	Coverage Δ
log/log.go	93.54% <ø> (ø)
app.go	84.15% <85.71%> (+0.50%)	⬆️
config/config.go	55.84% <100.00%> (ø)

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