The block height validation is gated by the startup option
`con_blockheightinheader`, accesible in custom chains only
using option `chain=<name>`. Only if set to true will this
field be (de)serialized and evaluated in consensus logic.
Otherwise the field is simply ignored, other than being
stored in memory as the default value 0.
fa5587fe71 qa: wait_for_verack by default (MarcoFalke)
Pull request description:
This removes the need to do so manually every time a connection is added.
Tree-SHA512: a46c92cb4df41e30778b42b9fd3dcbd8d2d82aa7503d1213cb1c1165034f648d8caee01c292e2d87d05b0f71696996eef5be8a753f35ab49e5f66b0e3bf29f21
