Fix camera texture aspect ratio in hardware renderer

It wasn't respecting the map's pixel ratio setting. This wouldn't have
been very noticeable with the default pixel ratio of 1.2 but it was
very obvious with 1.8.

src/rendering/hwrenderer/hw_entrypoint.cpp

@@ -343,7 +343,7 @@ sector_t* RenderView(player_t* player)
 					screen->RenderTextureView(camtex, [=](IntRect& bounds)
 						{
 							FRenderViewpoint texvp;
-							float ratio = camtex->aspectRatio;
+							float ratio = camtex->aspectRatio / Level->info->pixelstretch;
 							RenderViewpoint(texvp, camera, &bounds, fov, ratio, ratio, false, false);
 						});
 				});