Scheduled jobs could be executed on the Commerce Manager site

Steps to reproduce

When a scheduled job is started automatically there is no control over what site that will execute it. It could just as well be the Commerce Manager site, as a frontend site. Executing the job in the Commerce Manager site can cause problems, since it does not have the partner code.

It is possible to disable a site from running scheduled jobs by setting the config value enableScheduler to false in the episerver.config's applicationSettings element. If this configuration file is missing, it can be added to web.config (with the proper configSection) guided by the configuration setting of any CMS site.

Setting the Scheduler to be disabled should be the default config for the Commerce Manager site.