[API] get rid of warning: Called 'load' without the safe option
The API server, when using our default configuration, prints this warning on every startup:
Called 'load' without the :safe option -- defaulting to safe mode. You can avoid this warning in the future by setting the SafeYAML::OPTIONS[:default_mode] option (to :safe or :unsafe).
There should be no warnings when starting up the server and running rake tasks.