Problem in migration, an Orchard bug necessitates to drop a default constraint on CIndex

Unfortunately in v1 the CIndex was declared as a string, it is an int
* BUT THERE IS A BUG IN ORCHARD 1.7 un til actual 1.7.2
https://orchard.codeplex.com/workitem/19298
* this bug when droping a clumn does not chack for constraint and sql
server needs first droping the constraint
* YOU MUST DROP THE CONTRAINT by hand either using SQL Server Management
Studio, either using a script as expliend down here
* A way to find the name of a default constraint for a given table and
column could be something like this:
declare @column nvarchar(128)
declare @table nvarchar(128)

set @table = 'table1'
set @column = 'column_1'

select dc."name" as "DF_constraint"
from sys.default_constraints dc
join sys.columns c on c.default_object_id = dc.object_id
where dc.parent_object_id = OBJECT_ID(@table)
and c."name" = @column
* when the constraint is dropped, you can run the update module.