config: close file even if we fail to read it
If we get an exception from cfg.read(), we would not close the file
before this patch. This patch uses a context manager to make sure we
close it.
Differential Revision: https://phab.mercurial-scm.org/D7626
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false