glx: Explicitly reject servers that only support GLX 1.0

glx: Explicitly reject servers that only support GLX 1.0

__glXInitialize calls AllocAndFetchScreenConfigs.
AllocAndFetchScreenConfigs unconditionally sends a glXQuerySeverString
request to the server.  This request is only supported with GLX 1.1 or
later, so we were already implicitly incompatible with GLX 1.0
servers.  How many more similar bugs lurk in the code that nobody has
noticed in years?

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Eric Anholt <eric@anholt.net>