Fix TypeError in graph commands

[dvora-h]

Pull Request check-list

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Description of change

closes #2033

[codecov-commenter]

Codecov Report

Merging #2050 (a530089) into master (8d949a3) will decrease coverage by 0.01%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master    #2050      +/-   ##
==========================================
- Coverage   92.17%   92.15%   -0.02%     
==========================================
  Files         100      100              
  Lines       21024    21028       +4     
==========================================
+ Hits        19378    19379       +1     
- Misses       1646     1649       +3     

Impacted Files	Coverage Δ
redis/commands/graph/commands.py	84.81% <50.00%> (-0.91%)	⬇️
redis/commands/graph/execution_plan.py	74.74% <50.00%> (-0.52%)	⬇️
redis/asyncio/client.py	90.45% <0.00%> (-0.18%)	⬇️
tests/test_cluster.py	98.29% <0.00%> (ø)

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