Can't create new Image in ImageTexture

[Shadowblitz16]

Godot version:

3.2.3

OS/device including version:

Zorin OS 15.3 Nvidia GTX 650 450 proprietary driver

Issue description:

I can't seem to create a new image in the editor for a ImageTexture specificity on the TextureRect node

Steps to reproduce:

• Create a new TextureRect node
• Assign a ImageTexture in the texture slot
• Expand it and try to add a new Image in the image slot
• See that it fails

 drivers/gles2/rasterizer_storage_gles2.cpp:814 - Condition "texture->data_size == 0 && !texture->render_target" is true. Returned: Ref<Image>()


**Minimal reproduction project:**
<!-- A small Godot project which reproduces the issue. Drag and drop a zip archive to upload it. -->
[TextureRectImageTextureImageBug.zip](https://github.com/godotengine/godot/files/5594594/TextureRectImageTextureImageBug.zip)

[clayjohn]

Duplicate of #38112

Edit: Remember to search existing issues before opening a new one please!