Fix nested CTE leading to nested WITH problem

[jarodmeng]

Fixed #261

[codecov]

Codecov Report

Merging #262 (88b7bd1) into master (c98a2dd) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

❗ Current head 88b7bd1 differs from pull request most recent head d44ed77. Consider uploading reports for the commit d44ed77 to get more accurate results

@@            Coverage Diff             @@
##           master     #262      +/-   ##
==========================================
- Coverage   34.32%   34.30%   -0.02%     
==========================================
  Files          46       46              
  Lines        1774     1775       +1     
==========================================
  Hits          609      609              
- Misses       1165     1166       +1     

Files	Coverage Δ
R/dbplyr-src.R	20.00% <0.00%> (-0.28%)	⬇️

📣 Codecov offers a browser extension for seamless coverage viewing on GitHub. Try it in Chrome or Firefox today!