Reproduction steps:
1. Open the attached project;
2. Build the scene "BugScene";
3. Open built game and resize the window;
4. Observe the RenderTexture plane;

Actual result: when the window is resized, the RenderTexture is destroyed and the plane becomes black.

Expected result: the RenderTexture should not be destroyed and the plane should have the texture.

Reproduced with: 5.5.0b1, 5.5.2p4
Not reproducible with: 5.6.0f2, 2017.1.0a5