remove the map usage

[codecov[bot]]

Codecov Report

Merging #3296 (1821e40) into future/peggy2 (efe6269) will decrease coverage by 0.09%. The diff coverage is 85.50%.

:exclamation: Current head 1821e40 differs from pull request most recent head 6045e82. Consider uploading reports for the commit 6045e82 to get more accurate results

@@                Coverage Diff                @@
##           future/peggy2    #3296      +/-   ##
=================================================
- Coverage          48.27%   48.18%   -0.10%     
=================================================
  Files                169      171       +2     
  Lines              14940    15102     +162     
=================================================
+ Hits                7213     7277      +64     
- Misses              7307     7389      +82     
- Partials             420      436      +16     

Impacted Files	Coverage Δ
cmd/ebrelayer/txs/relayToEthereum.go	0.00% <0.00%> (ø)
x/instrumentation/test_instrumentation.go	50.00% <ø> (ø)
cmd/sifnoded/cmd/gentx.go	61.90% <61.29%> (+1.24%)	:arrow_up:
x/tokenregistry/keeper/keeper.go	89.60% <64.28%> (-3.21%)	:arrow_down:
x/oracle/keeper/keeper.go	56.81% <68.00%> (+2.40%)	:arrow_up:
x/oracle/types/globalSequenceKey.go	81.81% <81.81%> (ø)
x/oracle/keeper/prophecy.go	84.29% <90.90%> (-0.24%)	:arrow_down:
x/oracle/types/validatorWhiteList.go	90.90% <90.90%> (ø)
x/oracle/keeper/validatorWhiteList.go	87.50% <92.85%> (+1.34%)	:arrow_up:
x/oracle/keeper/witnessLockBurnSequence.go	92.85% <92.85%> (ø)
... and 31 more