Remove -ftrapv compile flag

It crashes my client with libav error

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Merge branch 'issue-196' of https://github.com/pgalisz/bluecherry-client

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
remove RU translations
bump version to 2.1.6 and update debian changelog