Redmine 3.4.4

db/migrate/048_allow_null_version_effective_date.rb

@@ -0,0 +1,9 @@
+class AllowNullVersionEffectiveDate < ActiveRecord::Migration
+  def self.up
+    change_column :versions, :effective_date, :date, :default => nil, :null => true
+  end
+
+  def self.down
+    raise IrreversibleMigration
+  end
+end