Change email subject content sent from CI system

Subject line changed from showing a useless long line representing
the SSH address of codereview to showing a shorter line stating
the project that was built and the build number. This one is
easier to read and works better on mobile devices that pick up
email.

Task-number: QTQAINFRA-815
Change-Id: Ie08bbd66d2fc97acfcc2011462317994b6e9075b
Reviewed-by: Liang Qi <liang.qi@digia.com>
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>
Reviewed-by: Sergio Ahumada <sahumada@blackberry.com>
Reviewed-by: Simo Fält <simo.falt@digia.com>