Change behavior: the old JoinRequest is destroyed now
Change behavior: the old JoinRequest is destroyed now

The Activity associated to it still exists, need to be sure that it
won't cause breaks in other places (workers for example). The new
Activity will be used to send mails.

mconf/mconf-web,becueb/MconfWeb,mconftec/mconf-web-santacasa,mconf-ufrgs/mconf-web,fbottin/mconf-web,mconf-ufrgs/mconf-web,lfzawacki/mconf-web,mconftec/mconf-web-mytruecloud,mconftec/mconf-web-santacasa,mconftec/mconf-web-uergs,mconftec/mconf-web-santacasa,mconf/mconf-web,akratech/Akraconference,mconf/mconf-web,akratech/Akraconference,mconftec/mconf-web-mytruecloud,fbottin/mconf-web,mconftec/mconf-web-uergs,lfzawacki/mconf-web,amreis/mconf-web,mconf-rnp/mconf-web,mconftec/mconf-web-santacasa,mconftec/mconf-web-mytruecloud,akratech/Akraconference,fbottin/mconf-web,mconf/mconf-web,mconftec/mconf-web-uergs,mconf-rnp/mconf-web,mconf-rnp/mconf-web,lfzawacki/mconf-web,becueb/MconfWeb,becueb/MconfWeb,lfzawacki/mconf-web,mconftec/mconf-web-mytruecloud,amreis/mconf-web,fbottin/mconf-web,mconf-rnp/mconf-web,akratech/Akraconference,amreis/mconf-web,mconf-ufrgs/mconf-web,becueb/MconfWeb,amreis/mconf-web,mconftec/mconf-web-uergs,mconf-ufrgs/mconf-web