test: suppress deprecation warning

with openjdk-1.8 maven fail to compile code with
deprecated API. As suggestion in javadoc does not work,
suppress deprecation.

Acked-by: Paul Millar
Acked-by: Gerd Behrmann
Target: master
(cherry picked from commit bfc2e9446e6b71569b5c17cf8212253cb6e9944d)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>