Use the tenant name as default organization name

This way we'll avoid having all tenant organizations named "CONSUL" by
default, and we'll also use different email senders per tenant, which
will reduce the change of the emails being marked as spam.

db/dev_seeds/settings.rb

@@ -6,12 +6,10 @@ section "Creating Settings" do
     "feature.featured_proposals": "true",
     "feature.map": "true",
     "instagram_handle": "CONSUL",
-    "mailer_from_name": "CONSUL",
     "meta_description": "Citizen participation tool for an open, "\
                         "transparent and democratic government",
     "meta_keywords": "citizen participation, open government",
     "meta_title": "CONSUL",
-    "org_name": "CONSUL",
     "proposal_code_prefix": "MAD",
     "proposal_notification_minimum_interval_in_days": 0,
     "telegram_handle": "CONSUL",