- add config value min_capacity_sat that will replaces the magic value
min_effective_htlc_capacity = AMOUNT_MSAT(1000000)
- add config switch min_capacity_sat
This will add the testnet config copyNpaste to test_utils.c,
so that the test stups can set these.
Alternatively, to reduce code duplication, we can move the
testnet_config and mainnet_config from options.c to options.h.