mapi: remove non applicable HAVE_DIX_CONFIG_H hunk

Seeming artefact from when the xserver build was diving directly into
mesa's tree.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/mapi/glapi/glapi_priv.h

@@ -27,10 +27,6 @@
 #define _GLAPI_PRIV_H
 
 
-#ifdef HAVE_DIX_CONFIG_H
-#include <dix-config.h>
-#include "glapi/mesa.h"
-#else /* HAVE_DIX_CONFIG_H */
 #define GL_GLEXT_PROTOTYPES
 #include "GL/gl.h"
 #include "GL/glext.h"
@@ -44,8 +40,6 @@ typedef int GLclampx;
 typedef void *GLeglImageOES;
 #endif
 
-#endif /* HAVE_DIX_CONFIG_H */
-
 #include "glapi/glapi.h"