run-resinhup-ssh.sh: Make sure a certain app belongs to a user
run-resinhup-ssh.sh: Make sure a certain app belongs to a user

Filtering only by app name can end up updating users which have the same
app name. In order to avoid this, app argument was updated to have a user:app
format and the filtering is now done by username and application name.

Signed-off-by: Andrei Gherzan <8dc7c09356db0b1762fb140617d7375c0a5a4131@resin.io>

resin-os/meta-resin,resin-os/meta-resin,resin-os/meta-resin,resin-os/meta-resin