fixup: cancel overbright on fullbright

Author: illwieckz

src/engine/renderer/tr_shade.cpp

@@ -1094,7 +1094,8 @@ static void Render_lightMapping( shaderStage_t *pStage )
 	/* HACK: use sign to know if there is a light or not, and
 	then if it will receive overbright multiplication or not. */
 	bool blendFunc_dstColor = ( pStage->stateBits & GLS_SRCBLEND_BITS ) == GLS_SRCBLEND_DST_COLOR;
-	float lightFactor = ( pStage->shaderHasNoLight && !blendFunc_dstColor ) ? tr.mapLightFactor : - tr.mapLightFactor;
+	bool noLight = pStage->shaderHasNoLight || lightMode == lightMode_t::FULLBRIGHT;
+	float lightFactor = ( noLight && !blendFunc_dstColor ) ? tr.mapLightFactor : - tr.mapLightFactor;
 	gl_lightMappingShader->SetUniform_LightFactor( lightFactor );
 
 	// u_ColorModulate