reduce cache log

[atellwu]

Motivation:

reduce cache print size , because cache-digest.log is too large when pubSize is huge

[codecov-io]

Codecov Report

Merging #88 into master will decrease coverage by 0.04%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master      #88      +/-   ##
============================================
- Coverage     62.38%   62.33%   -0.05%     
  Complexity       44       44              
============================================
  Files           429      429              
  Lines         15446    15445       -1     
  Branches       1488     1488              
============================================
- Hits           9636     9628       -8     
- Misses         4792     4799       +7     
  Partials       1018     1018

Impacted Files	Coverage Δ	Complexity Δ
...fa/registry/server/data/cache/CacheDigestTask.java	76.31% <100%> (-0.61%)	0 <0> (ø)
...ting/sessionserver/disconnect/DisconnectEvent.java	58.33% <0%> (-8.34%)	0% <0%> (ø)
.../registry/server/data/renew/DatumLeaseManager.java	83.47% <0%> (-5.79%)	0% <0%> (ø)
...a/registry/server/meta/store/DataStoreService.java	66.16% <0%> (-0.38%)	0% <0%> (ø)
...istry/server/meta/resource/MetaDigestResource.java	60% <0%> (+7.5%)	0% <0%> (ø)	⬇️

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