ref: gl: remove vid_gamma/vid_brightness changed cvar value check

ref/gl/gl_backend.c

@@ -560,8 +560,6 @@ qboolean VID_CubemapShot( const char *base, uint size, const float *vieworg, qbo
 	// use client vieworg
 	if( !vieworg ) vieworg = RI.vieworg;
 
-	R_CheckGamma();
-
 	for( i = 0; i < 6; i++ )
 	{
 		// go into 3d mode

ref/gl/gl_rmain.c

@@ -985,31 +985,6 @@ void R_RenderScene( void )
 	R_EndGL();
 }
 
-/*
-===============
-R_CheckGamma
-===============
-*/
-void R_CheckGamma( void )
-{
-	if( gEngfuncs.R_DoResetGamma( ))
-	{
-		// paranoia cubemaps uses this
-		gEngfuncs.BuildGammaTable( 1.8f, 0.0f );
-
-		// paranoia cubemap rendering
-		if( gEngfuncs.drawFuncs->GL_BuildLightmaps )
-			gEngfuncs.drawFuncs->GL_BuildLightmaps( );
-	}
-	else if( FBitSet( vid_gamma->flags, FCVAR_CHANGED ) || FBitSet( vid_brightness->flags, FCVAR_CHANGED ))
-	{
-		gEngfuncs.BuildGammaTable( vid_gamma->value, vid_brightness->value );
-		glConfig.softwareGammaUpdate = true;
-		GL_RebuildLightmaps();
-		glConfig.softwareGammaUpdate = false;
-	}
-}
-
 /*
 ===============
 R_BeginFrame
@@ -1025,8 +1000,6 @@ void R_BeginFrame( qboolean clearScene )
 		pglClear( GL_COLOR_BUFFER_BIT );
 	}
 
-	R_CheckGamma();
-
 	R_Set2DMode( true );
 
 	// draw buffer stuff

ref/gl/gl_rsurf.c

@@ -3756,9 +3756,6 @@ void GL_RebuildLightmaps( void )
 	if( !ENGINE_GET_PARM( PARM_CLIENT_ACTIVE ) )
 		return; // wait for worldmodel
 
-	ClearBits( vid_brightness->flags, FCVAR_CHANGED );
-	ClearBits( vid_gamma->flags, FCVAR_CHANGED );
-
 	// release old lightmaps
 	for( i = 0; i < MAX_LIGHTMAPS; i++ )
 	{
@@ -3874,10 +3871,6 @@ void GL_BuildLightmaps( void )
 		// build lightmaps on the client-side
 		gEngfuncs.drawFuncs->GL_BuildLightmaps( );
 	}
-
-	// now gamma and brightness are valid
-	ClearBits( vid_brightness->flags, FCVAR_CHANGED );
-	ClearBits( vid_gamma->flags, FCVAR_CHANGED );
 }
 
 void GL_InitRandomTable( void )