Merge branch 'gl-signpost-fix' into 'next'

Make HWR_AllowModel check for SPR2_SIGN instead of S_PLAY_SIGN

Closes #1066

See merge request !2076

src/hardware/hw_md2.c

@@ -1146,7 +1146,7 @@ static void HWR_GetBlendedTexture(patch_t *patch, patch_t *blendpatch, INT32 ski
 static boolean HWR_AllowModel(mobj_t *mobj)
 {
 	// Signpost overlay. Not needed.
-	if (mobj->state-states == S_PLAY_SIGN)
+	if (mobj->sprite2 == SPR2_SIGN)
 		return false;
 
 	// Otherwise, render the model.