Fix: --vimemu option did not work together with --lightweight

This patch allows to use the --vimemu option with both CB
and LB version of OSM.
In the LB case, the vim-emu container is attached to OSM's
custom docker network 'netOSM' to be reachable from the RO.

Change-Id: I5eca6d92dfed22597d263ab1a73637490fac66f7
Signed-off-by: peusterm <manuel.peuster@uni-paderborn.de>