Revert "stbi: fix loading image from memory (#15981); breaks UI's rectangle example on macos, probably others too"

This reverts commit 07d5612347.

vlib/gg/image.c.v

@@ -227,9 +227,8 @@ pub fn (mut ctx Context) create_image_from_memory(buf &u8, bufsize int) Image {
 		ok: stb_img.ok
 		data: stb_img.data
 		ext: stb_img.ext
+		id: ctx.image_cache.len
 	}
-	img.init_sokol_image()
-	img.id = ctx.image_cache.len
 	ctx.image_cache << img
 	return img
 }

vlib/stbi/stbi.c.v

@@ -108,21 +108,13 @@ pub fn load(path string) ?Image {
 
 // load_from_memory load an image from a memory buffer
 pub fn load_from_memory(buf &u8, bufsize int) ?Image {
-	return load_from_memory_with_channels(buf, bufsize, 0)
-}
-
-// load_from_memory_with_channels an image from a memory buffer, with user-defined number of image channels
-pub fn load_from_memory_with_channels(buf &u8, bufsize int, desired_channels int) ?Image {
 	mut res := Image{
 		ok: true
 		data: 0
 	}
+	flag := C.STBI_rgb_alpha
 	res.data = C.stbi_load_from_memory(buf, bufsize, &res.width, &res.height, &res.nr_channels,
-		desired_channels)
-	if desired_channels == 4 && res.nr_channels == 3 {
-		// Fix an alpha png bug
-		res.nr_channels = 4
-	}
+		flag)
 	if isnil(res.data) {
 		return error('stbi_image failed to load from memory')
 	}