fix: stock ageing report not working

[rohitwaghchaure]

Issue

Getting below error while accessing the stock ageing report

Traceback (most recent call last):
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/app.py", line 64, in application
    response = frappe.api.handle()
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/api.py", line 58, in handle
    return frappe.handler.handle()
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/handler.py", line 30, in handle
    data = execute_cmd(cmd)
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/handler.py", line 70, in execute_cmd
    return frappe.call(method, **frappe.form_dict)
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/__init__.py", line 1107, in call
    return fn(*args, **newargs)
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/__init__.py", line 564, in wrapper_fn
    retval = fn(*args, **get_newargs(fn, kwargs))
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/desk/query_report.py", line 227, in run
    result = generate_report_result(report, filters, user, custom_columns)
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/desk/query_report.py", line 75, in generate_report_result
    res = report.execute_script_report(filters)
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/core/doctype/report/report.py", line 123, in execute_script_report
    res = self.execute_module(filters)
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/frappe/frappe/core/doctype/report/report.py", line 140, in execute_module
    return frappe.get_attr(method_name)(frappe._dict(filters))
  File "/home/frappe/benches/bench-version-13-2020-11-10/apps/erpnext/erpnext/stock/report/stock_ageing/stock_ageing.py", line 26, in execute
    earliest_age = date_diff(to_date, fifo_queue[0][1])
IndexError: list index out of range

backport #23923