Entries in the input manager of macOS standalone player cannot be changed - trying to do so makes the player unresponsive.

Steps to reproduce:
1) Create a new project.
2) Build and Run for macOS.
3) Open 'Input' tab.
4) Double click on any entry to change its value.
5) When the prompt, asking to press a key appears, press any key.

The input manager doesn't react to input - all key presses are ignored, the player cannot be terminated without force quitting it.
This does not occur on Windows or Linux.

Reproduced on:
2017.1.0b1, 5.6.0f3, 5.6.0b1 (regression introduced here)

Did not reproduce:
5.6.0a6, 5.6.0a1, 5.5.3p1

Fixed in - 2017.2.0b3