fix: enable allow negative stock by default in reposts (frappe#29331)

Negative stock validation is done BEFORE reposting as such it's not
required to be performed again and most likely this fails on old
intermediate data where user has no clue why it failed.

erpnext/stock/doctype/repost_item_valuation/repost_item_valuation.json

@@ -1,7 +1,7 @@
 {
  "actions": [],
  "autoname": "REPOST-ITEM-VAL-.######",
- "creation": "2020-10-22 22:27:07.742161",
+ "creation": "2022-01-11 15:03:38.273179",
  "doctype": "DocType",
  "editable_grid": 1,
  "engine": "InnoDB",
@@ -129,7 +129,7 @@
    "reqd": 1
   },
   {
-   "default": "0",
+   "default": "1",
    "fieldname": "allow_negative_stock",
    "fieldtype": "Check",
    "label": "Allow Negative Stock"
@@ -177,7 +177,7 @@
  "index_web_pages_for_search": 1,
  "is_submittable": 1,
  "links": [],
- "modified": "2021-11-24 02:18:10.524560",
+ "modified": "2022-01-18 10:57:33.450907",
  "modified_by": "Administrator",
  "module": "Stock",
  "name": "Repost Item Valuation",
@@ -227,5 +227,6 @@
   }
  ],
  "sort_field": "modified",
- "sort_order": "DESC"
-}
+ "sort_order": "DESC",
+ "states": []
+}

erpnext/stock/doctype/repost_item_valuation/repost_item_valuation.py

@@ -27,8 +27,7 @@ def reset_field_values(self):
 			self.item_code = None
 			self.warehouse = None
 
-		self.allow_negative_stock = self.allow_negative_stock or \
-				cint(frappe.db.get_single_value("Stock Settings", "allow_negative_stock"))
+		self.allow_negative_stock = 1
 
 	def set_company(self):
 		if self.based_on == "Transaction":