old_parent field in account is linked to Account now, it will fix account renaming bug

accounts/doctype/account/account.txt

@@ -455,7 +455,8 @@
 		'description': "Don't delete this field at any cost",
 		'doctype': 'DocField',
 		'fieldname': 'old_parent',
-		'fieldtype': 'Data',
+		'fieldtype': 'Link',
+		'options': 'Account', 
 		'hidden': 1,
 		'idx': 24,
 		'label': 'Old Parent',
@@ -517,4 +518,4 @@
 		'oldfieldtype': 'Small Text',
 		'permlevel': 1
 	}
-]
+]