[JTC] Hold position & goal_time>0: Infinite loop

[christophfroehlich]

          I think I've found a possible issue, do you have set a `goal_time_tolerance>0`? If the time tolerance is exceeded, the PID controller will be deactivated even in hold position mode.

Originally posted by @christophfroehlich in #558 (comment)

This could happen if the JTC can't hold the position (wrong PID tuning, effort limit,..), then it might enter a loop setting a new hold position again and again.