Bug#1111779: gambas3: patch to support building w/ mongo-c-driver >= 2.0

[Bastian Germann]

Control: severity -1 wishlist
Control: unblock 1112375 by -1

I had already dropped the affected component before this patch arrived.
Upstream does not consider it stable.

I am going to leave this bug open, so anyone needing the patch may get
it.