VFS-5338 Set onezone_domain variable on all onepanel nodes
VFS-5338 Set onezone_domain variable on all onepanel nodes

This variable was set only for onepanel nodes on op_worker hosts.
This caused incorrect results of calls such as
service_oneprovider:get_oz_domain/0 and in some cases prevented
access to the cluster from unified gui (by breaking CORS headers).

This commits changes behaviour to distribute the variable
to all onepanel nodes.

onedata/onepanel,onedata/onepanel