It is possible to add the same event several times to the same input action

[mieldepoche]

Tested versions

v4.3.dev.custom_build [11d376813]

System information

linux

Issue description

in Project > Project Settings > Input Map:

you can add the same key/button several times to the same action.

Steps to reproduce

• add the same event twice to the same action

Minimal reproduction project (MRP)

any

[toadkarter]

I'd like to work on this if that's ok - I'll have a look but I presume it should be just checking that the newly input key is not the same as the ones currently bound.