fix: replaced batch references

lms/www/batch/join.html

@@ -51,7 +51,7 @@ frappe.ready(() => {
         frappe.call({
             "method": "lms.lms.doctype.lms_batch_membership.lms_batch_membership.create_membership",
             "args": {
-                "batch": {{ batch.name }},
+                "batch_old": {{ batch.name }},
                 "course": {{ batch.course }}
             },
             "callback": (data) => {

lms/www/batch/learn.py

@@ -72,7 +72,7 @@ def get_context(context):
 	context.page_extensions = get_page_extensions(context)
 	context.page_context = {
 		"course": context.course.name,
-		"batch": context.batch_old,
+		"batch_old": context.batch_old,
 		"lesson": context.lesson.name if context.lesson.name else "New Lesson",
 		"is_member": context.membership is not None,
 	}