remove default code for existing projects

As copied projects are to receive a `gray`/not set state, I assume that the same is to be true for new projects and hence also for every project where no user has made an explicit statement

db/migrate/20190923111902_add_project_status_reporting.rb

@@ -6,20 +6,5 @@ class AddProjectStatusReporting < ActiveRecord::Migration[6.0]
       table.integer :code
       table.timestamps
     end
-
-    reversible do |change|
-      change.up do
-        project_status_for_existing_projects
-      end
-    end
-  end
-
-  def project_status_for_existing_projects
-    insert_sql = <<-SQL
-      INSERT into project_statuses
-      SELECT id AS project_id, #{Project::Status.codes['on_track']} as code FROM projects
-    SQL
-
-    insert Arel.sql(insert_sql)
   end
 end