Reproduction steps:
1. Create new project
2. Build and Run for standalone
3. Open Input tab on game launcher
4. Double click on any of the input areas
5. Try to assign gamepad/controller input.
Notice: that nothing is happening until keyboard key is pressed.

Expected behaviour: Gamepad/Controller input is assigned to the corresponding input.
Actual result: Input assign does not react to gamepad/controller input.

Reproduced on: OSX 10.13
Works as expected on Windows.

Reproduced on versions: Unity 2017.1.2p3, 20172.0p4, 2017.3.0b11, 2018.1.0a6

Note: Unity 2017.1.2p3 crashes when input configuration window appears.