Set breakpoints before connect() in JS debugging unit test

connect() starts the JS engine. Any break point set after that may be
missed because the engine has already passed its location when the
breakpoint request arrives. The problem can easily be visualized by
inserting an artificial delay (e.g. sleep(1)) between connect() and
setBreakpoint().
I'm also removing a piece of dead code that gets that wrong and has
never actually worked.

Change-Id: Ie4410ac3eaf89f02993c653b17148c14048652ab
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>