include/nlohmann/json.hpp conflicted in update(const_iterator, const_iterator, bool):
kept develop's prepare_update() helper, which already creates the object
before setting its type (the same fix this branch makes elsewhere).
single_include/nlohmann/json.hpp was regenerated via `make amalgamate`
instead of being hand-resolved.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>