OpenGL2: Readd r_deluxeSpecular.

https://github.com/ioquake/ioq3/issues/369

code/renderergl2/tr_local.h

@@ -1718,6 +1718,7 @@ extern  cvar_t  *r_deluxeMapping;
 extern  cvar_t  *r_parallaxMapping;
 extern  cvar_t  *r_cubeMapping;
 extern  cvar_t  *r_cubemapSize;
+extern  cvar_t  *r_deluxeSpecular;
 extern  cvar_t  *r_pbr;
 extern  cvar_t  *r_baseNormalX;
 extern  cvar_t  *r_baseNormalY;