debian-stretch-titan: do not install unneeded dependencies
By default, Debian's package manager (apt) would install as many dependencies as possible, including optional (recommended and suggested) ones.
Package 'eclipse-titan' recommends 'default-jdk', which is absolutely not needed for osmo-ttcn3-hacks, and in its turn depends on +100500 more packages like xorg, wayland, etc.
This change significantly reduces total amount of dependencies and the overall build time by disabling installation of recommended and suggested dependencies.
