fix: modify filters for account in journal entry (#35626)

diff --git a/erpnext/accounts/doctype/journal_entry/journal_entry.js b/erpnext/accounts/doctype/journal_entry/journal_entry.js
index b31cc32..6d9e320 100644
--- a/erpnext/accounts/doctype/journal_entry/journal_entry.js
+++ b/erpnext/accounts/doctype/journal_entry/journal_entry.js
@@ -575,7 +575,7 @@
 		};
 		if(!frm.doc.multi_currency) {
 			$.extend(filters, {
-				account_currency: frappe.get_doc(":Company", frm.doc.company).default_currency
+				account_currency: ['in', [frappe.get_doc(":Company", frm.doc.company).default_currency, null]]
 			});
 		}
 		return { filters: filters };
diff --git a/erpnext/accounts/doctype/journal_entry_template/journal_entry_template.js b/erpnext/accounts/doctype/journal_entry_template/journal_entry_template.js
index 5ebdf61..7d80754 100644
--- a/erpnext/accounts/doctype/journal_entry_template/journal_entry_template.js
+++ b/erpnext/accounts/doctype/journal_entry_template/journal_entry_template.js
@@ -28,7 +28,7 @@
 
 			if(!frm.doc.multi_currency) {
 				$.extend(filters, {
-					account_currency: frappe.get_doc(":Company", frm.doc.company).default_currency
+					account_currency: ['in', [frappe.get_doc(":Company", frm.doc.company).default_currency, null]]
 				});
 			}