CI: update JRuby 9.2 (to 9.2.6)
CI: update JRuby 9.2 (to 9.2.6)

it is expected to have fixed a mutex bug

adhearsion/adhearsion,adhearsion/adhearsion,cloudvox/adhearsion,cloudvox/adhearsion,cloudvox/adhearsion,adhearsion/adhearsion,adhearsion/adhearsion,cloudvox/adhearsion