[Bug 43971] Wine 2.20 Bcrypt compilation fails under older linux systems while Wine 2.0.3 compiles fine

https://bugs.winehq.org/show_bug.cgi?id=43971

--- Comment #14 from Zhenya  ---
Hello again! Thank you for a fix of this bug. I see that Wine 3.0 is
successfully compiling on my SLES 11.

I see that libGnuTLS 2.4 supports bcrypt, but it was error when Wine trying to
use it. #6 says that "key" variable is already defined in libGnuTLS 2.4 headers
but isn't defined in 2.6 and later.

Can you add a condition for < 2.6? Somethink like "if libGnuTLS < 2.6 then
define key2, else define key"?