cleanup keys table from translations engine

otherwise we can't create a new keys table

config/deploy.rb

@@ -18,7 +18,7 @@ set :application, "crabgrass"
 set :user, "crabgrass"
 
 set :repository, "git://labs.riseup.net/crabgrass-core.git"
-set :branch, "develop"
+set :branch, "bugfix/fix-migrations"
 
 deploy_host = ""
 staging_host = "we.dev.riseup.net"

db/migrate/20110215132532_install_acts_as_locked.rb

 class InstallActsAsLocked < ActiveRecord::Migration
   def self.up
+    drop_table :keys if ActiveRecord::Base.connection.table_exists? :keys
     create_table :keys do |p|
       p.integer :mask, :default => 0
       p.integer :locked_id