Regression with emacsclient on commit e3cebbb839fc94f314659bf667c6790edebf4297

[Yuri D'Elia]

When using emacsclient, there's a new error which is emitted when the
first frame is created:

Debugger entered--Lisp error: (error "KEY must be an integer, cons, symbol, or 
string")
  key-description([#<buffer *scratch*>])
  undefined()

To reproduce, call `emacsclient -c` without an existing emacs instance
and/or start emacs --daemon and create a new frame.

The error is shown only when creating the _first_ frame.

I bisected the error down to commit
e3cebbb839fc94f314659bf667c6790edebf4297: Replay key if kboard is
interrupted while initializing (Bug#37782)

I cannot trigger this regression bug by simply starting emacs without a
daemon.