Add test is column_name is in _columns when testing field type for issue1194

add_raw_column is used in _update_history_table and column_name can any more
exist or not yet instanciate in the Model

trytond/backend/sqlite/table.py

@@ -179,7 +179,9 @@ class TableHandler(TableHandlerInterface):
         column_type = column_type[1]
         default = ''
         from trytond.model import fields
-        if isinstance(self._model._columns[column_name], (fields.Integer, fields.Float)):
+        if column_name in self._model._columns and \
+                isinstance(self._model._columns[column_name],
+                        (fields.Integer, fields.Float)):
             default = ' DEFAULT 0'
         self.cursor.execute(('ALTER TABLE "%s" ADD COLUMN "%s" %s' + default) %
                        (self.table_name, column_name, column_type))