GLX: Set GlxServerExports::{major,minor}Version

Commit 56c0a71f incremented the
GLXSERVER_VENDOR_ABI_MINOR_VERSION define, but this define was not actually
being used to set glxServer.minorVersion.

Update the initializer for glxServer to use the correct version numbers.

Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
(cherry picked from commit b4231d69)