Assertion failed on expression: 'index < kMaxChannels' exception thrown while setting cluster input index size.

Steps to repro:
1. Open a new project.
2. Edit > Settings
3. Select Cluster Input from the left panel.
4. In the right panel set the size value under input section.
5. Increase the index value of the element.

Actual Result:
Assertion failed on expression: 'index < kMaxChannels' exception thrown

Reproducible on:
2018.3.0a5, 2018.3.0a4

Note: Unified settings are introduced in 2018.3.0a4.

Environment:
Occurring only on Windows.