Revert "ENH: Improve performance for df.__setitem__ with list-like indexers"
Reverts pandas-dev/pandas#38148 xref https://github.com/pandas-dev/pandas/issues/37784#issuecomment-736200698
flaky test on the Travis push ci job
=========================== short test summary info ============================
FAILED pandas/tests/io/test_html.py::TestReadHtml::test_banklist_url_positional_match[bs4]
= 1 failed, 144300 passed, 3144 skipped, 1435 xfailed, 58 warnings in 2953.57s (0:49:13) =