Update component leads to Jean-Michel

From Moodle Message from Jean-Michel regarding:

https://moodle.org/plugins/view.php?plugin=qtype_multichoiceset

CONTRIB trackers issue for that component are send to Adriane as he is listed as the component leader, but I mailed him and he answered that he has no more time for Moodle coding.

He agree that I become the new component leader and it will be a lot more easy for me to follow trackers issues and fix bugs that way.

The same problem exists for qtype_ddmatch (drag and drop matching) which has Itamar Tzadok listed as component leader but this must be a mistake as to my best knowledge Itamar has never maintained this plugin : Adriane Boyd maintained it for Moodle 1.9 and Moodle 2.0 and after that I took the task to maintain it.

And finally qtype_Algebra has Roger Moore as component leader but I was unable to reach him and he don't seems to to do Moodle coding anymore.

For all these plugins it would simplify my task a lot if I was component leader as currently I must connect to the CONTRIB tracker from time to time and verify no new issue was created.