Qt (KeyPressEvent): Missing break in switch (CID 1159205, 1159206, 1159208, 1159209)

Change-Id: I40b7c7eefb269570e6a1c5c9ec310fa97840d42d
Reviewed-on: https://code.wireshark.org/review/5995
Reviewed-by: Anders Broman <a.broman58@gmail.com>