fix block hash mismatch error on subgraph

[ilovers]

• Targeted PR against correct branch (see CONTRIBUTING.md)

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.

• Wrote tests

• Updated relevant documentation (docs/)

• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md

• Reviewed Files changed in the github PR explorer

---

For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge PR #XYZ: [title]" (coding standards)

[codecov-commenter]

Codecov Report

Merging #116 (29274d7) into dev (bb168c5) will increase coverage by 0.01%.
The diff coverage is 0.00%.

❗ Current head 29274d7 differs from pull request most recent head 5ea945a. Consider uploading reports for the commit 5ea945a to get more accurate results

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@@            Coverage Diff             @@
##              dev     #116      +/-   ##
==========================================
+ Coverage   34.16%   34.17%   +0.01%     
==========================================
  Files         423      423              
  Lines       44266    44252      -14     
==========================================
+ Hits        15122    15125       +3     
+ Misses      28043    28027      -16     
+ Partials     1101     1100       -1     

Impacted Files	Coverage Δ
app/rpc/backend/backend.go	0.00% <0.00%> (ø)
app/rpc/namespaces/eth/api.go	0.00% <ø> (ø)
x/evm/keeper/abci.go	54.41% <0.00%> (ø)
x/evm/watcher/watcher.go	46.05% <0.00%> (-0.13%)	⬇️

... and 2 files with indirect coverage changes