The function wpa_config_get_line() is used by the wpa_supplicant config
file parser to retrieve the next non-comment non-blank line. We'll need
the same kind of functionality to implement the file-based external
password backend, so as a preparatory step this commit extracts the
function into its own standalone file in the utils package.
No functional changes are expected from this commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
e9f449ba59