fix thread_interruptible_loop

[nim65s]

Ok but what about this file? import dynamic_graph.sot.core.utils.thread_interruptible_loop
It basically get's an error because it imports: from dynamic_graph.script_shortcuts import optionalparentheses
Which in essence is not Matlab stuff.
So I guess another PR in dgp is needed to remove the Matlab stuff but I cannot do it from this PR.
This is why I disabled the unit-test from now.

Please let me know if you both (@jmirabel and @nim65s) are ok with this PR.

This is coming from dynamic-graph-python.
It used to be a way to directly test the SoT from a python interpreter.

I am attempting a revival of this part, mostly to have the SoT independent from ROS.

Originally posted by @olivier-stasse in #172 (comment)

[olivier-stasse]

I am testing that if removing .matlab is enough.
My guess is that it is.

[olivier-stasse]

Thanks @nim65s for opening this issue.