config: rename git_config_set_or_die to git_config_set

config: rename git_config_set_or_die to git_config_set

Rename git_config_set_or_die functions to git_config_set, leading
to the new default behavior of dying whenever a configuration
error occurs.

By now all callers that shall die on error have been transitioned
to the _or_die variants, thus making this patch a simple rename
of the functions.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>