Use rsync on server when transferring repositories

The REMOTE_COPY_CMD translates into %SCP% when running repo builds
on Windows. %SCP" translates into "c:\Program Files\..." which of cource
does not exist on servers as they run Unix style OS.

Always use rsync on the server side.

Change-Id: I69c63341e1236cb6c1f644767ddad2fc8e417c8c
Reviewed-by: Samuli Piippo <samuli.piippo@digia.com>
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>