keepalive: switch from thread to threading module
The thread module in py3 is renamed to _thread, but we can use
the high level threading module instead.
# See http://EditorConfig.org for the specificationroot = true[*.py]indent_size = 4indent_style = spacetrim_trailing_whitespace = true[*.{c,h}]indent_size = 8indent_style = tabtrim_trailing_whitespace = true