[3.7] bpo-6135: Fix subprocess.check_output doc to mention changes in 3.6 (GH-5564)#5572

gpshead merged 1 commit intopython:3.7python/cpython:3.7from

miss-islington:backport-fc1ce81-3.7miss-islington/cpython:backport-fc1ce81-3.7Copy head branch name to clipboard