toaster: don't kill toaster on start

toaster: don't kill toaster on start

There is no point of trying to kill django development server
when toaster starts because 'manage.py checksocket' command is already
used in the script code to check if development server port is occupied.

Even if Toaster is listening on another port, killing previous instance
looks quite implicit and doesn't solve anything as there are other
processes that might be still running.

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Michael Wood <michael.g.wood@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>