This doesn't cover external libs in general (which *could* be effected by
CFLAGS), but at least all our own objects are rebuilt.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
You will want to 'make distclean' after this.
I also removed libsecp; we use the one in in libwally anyway.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>