[net] Remove assert(nMaxInbound > 0)
[net] Remove assert(nMaxInbound > 0)

nMaxInbound might very well be 0 or -1, if the user prefers to keep
a small number of maxconnections.

Note: nMaxInbound of -1 means that the user set maxconnections
to 8 or less, but we still want to keep an additional slot for
the feeler connection.

Github-Pull: #9008
Rebased-From: fa1c3c2eb0a1853ed0e0662fc2bdbca51e05ccf5

martindale/elements,martindale/elements,martindale/elements,martindale/elements,martindale/elements,martindale/elements