[server/rql2sql] use VariableRef.is_equivalent explicitly instead of relying on __eq__ What we want to compare is the variable referenced by the VariableRef, we should make that explicit. Closes #6694406

if 'same_as' in schema:
    sync_schema_props_perms('same_as', syncperms=False)
sync_schema_props_perms('Bookmark', syncperms=False)