Removed redundant parser assignment

[ChrisAHolland]

parser is passed as a parameter when _add_aliases() is called in main(). However, parser is then re-declared on line 145 to the very same thing it is assigned before _add_aliases() is called (line 203).

This PR removes the redundant assignment of parser.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov-io]

Codecov Report

Merging #5152 into develop will decrease coverage by 0.00%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #5152      +/-   ##
===========================================
- Coverage    93.97%   93.97%   -0.01%     
===========================================
  Files          188      188              
  Lines        14548    14547       -1     
===========================================
- Hits         13672    13671       -1     
  Misses         876      876              

Impacted Files	Coverage Δ
awscli/clidriver.py	95.93% <ø> (-0.02%)	⬇️

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[ChrisAHolland]

CC @kyleknap @joguSD @stealthycoin @KaibaLopez
Would I be able to get a review?

[codecov-commenter]

Codecov Report

Merging #5152 into develop will decrease coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #5152      +/-   ##
===========================================
- Coverage    93.97%   93.95%   -0.03%     
===========================================
  Files          188      188              
  Lines        14548    14996     +448     
===========================================
+ Hits         13672    14089     +417     
- Misses         876      907      +31     

Impacted Files	Coverage Δ
awscli/clidriver.py	95.93% <ø> (-0.02%)	⬇️
awscli/customizations/eks/update_kubeconfig.py	97.19% <0.00%> (-0.75%)	⬇️
awscli/customizations/s3/fileinfo.py	100.00% <0.00%> (ø)
awscli/customizations/emr/helptext.py	100.00% <0.00%> (ø)
...customizations/cloudformation/artifact_exporter.py	98.86% <0.00%> (+0.23%)	⬆️
awscli/customizations/s3/utils.py	98.61% <0.00%> (+0.50%)	⬆️
awscli/customizations/emr/createcluster.py	98.86% <0.00%> (+0.56%)	⬆️
awscli/customizations/ecs/deploy.py	60.37% <0.00%> (+1.54%)	⬆️

---

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[ChrisAHolland]

@kdaily Can this be merged?

[justindho]

Forgot to click the approval button before merging, but the changes look good. Thanks @ChrisAHolland!