remove property 'bridges' from menshen config section

rename the property bridges in section [menshen] to localbridges so that it reflects menshens commandline flag --localbridges

After the MR review, we pass the information about enabled bridges directly to menshen without further configuration flag needed.

built on top of #4 (closed) and #5 (closed) which needs to be reviewed and merged first

change to be reviewed here: c5479c78