Make user.admin db column not null.

git-svn-id: file:///home/svn/framework3/trunk@10296 4d416f70-5f16-0410-b530-b9f4589650da

data/sql/migrate/025_add_user_admin.rb

@@ -2,7 +2,7 @@ class AddUserAdmin < ActiveRecord::Migration
 
 	# Add user admin flag and project member list.
 	def self.up
-		add_column :users, :admin, :boolean, :default => true
+		add_column :users, :admin, :boolean, :null => false, :default => true
 
 		create_table :project_members, :id => false do |t|
 			t.integer :workspace_id, :null => false