Godot: GLES2: "World Triplanar" in SpatialMaterial is broken

[ProbDenis]

Godot version:
Built from master (b77a411)

OS/device including version:
Manjaro Linux, Radeon RX 560

Issue description:
I tested my game in Godot 3.1 with the new GLES2 renderer and noticed the whole (3D) screen turning white. After some tinkering with the materials I found the cause. It happens when I use triplanar materials and check the "World Triplanar" flag. I'm using that a lot, and it seems to break the whole 3D view. Unchecking "World Triplanar" seems to fix it.

Steps to reproduce:

• Create a MeshInstance with a CubeMesh (or anything else).
• Assign a new SpatialMaterial.
• Check "Triplanar" for UV1.
• Check the "World Triplanar" flag.

[tagcup]

You can fix it by changing line 359 in drivers/gles2/shaders/scene.glsl

-       tangent = normalize((world_matrix * vec4(tangent, 0.0)), xyz);
+       tangent = normalize((world_matrix * vec4(tangent, 0.0)).xyz);

[akien-mga]

Thanks @tagcup, I'm pushing a PR with this fix.