gdrive: pop prefix kwarg

[efiop]

https://travis-ci.com/github/iterative/dvc/jobs/357157580#L8485

• ❗ I have followed the Contributing to DVC checklist.

• 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.

• ❌ I will check DeepSource, CodeClimate, and other sanity checks below. (We consider them recommendatory and don't expect everything to be addressed. Please fix things that actually improve code or fix bugs.)

Thank you for the contribution - we'll try to review it as soon as possible. 🙏

[codecov]

Codecov Report

Merging #4157 into master will increase coverage by 0.00%.
The diff coverage is 94.11%.

@@           Coverage Diff           @@
##           master    #4157   +/-   ##
=======================================
  Coverage   92.58%   92.59%           
=======================================
  Files         162      162           
  Lines       11293    11304   +11     
=======================================
+ Hits        10456    10467   +11     
  Misses        837      837           

Impacted Files	Coverage Δ
dvc/remote/oss.py	92.18% <50.00%> (-1.37%)	⬇️
dvc/remote/azure.py	94.25% <100.00%> (+0.13%)	⬆️
dvc/remote/base.py	95.15% <100.00%> (+0.15%)	⬆️
dvc/remote/gdrive.py	81.85% <100.00%> (+0.06%)	⬆️
dvc/remote/gs.py	94.21% <100.00%> (+0.09%)	⬆️
dvc/remote/s3.py	94.83% <100.00%> (+0.06%)	⬆️
dvc/version.py	83.33% <100.00%> (ø)

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