gen_default_broker_cfg.sh: Fixed issue supporting $MAILTO values containing '#'.
There was a 'sed' expression that choked when $MAILTO value contained a '#' character,
e.g. "#PerforceAdminsDistributionList" (where the '#' indicates a distribution list on
an Exchange Server).
The sed utility allows for various delimiter characters, e.g. ':', '/', '#'. The idea is
to select one that on won't conflict with whatever your are substituting. The
prior version assumed '#' was a good delimter for $MAITO values, but that has proven
not to be the case. Now the '/'' character is used for that particular sed expression
instead.