[hotfix] fixes for UnicodeDecodeError

[mbauskar]

Traceback (most recent call last):
  File "/home/frappe/frappe-bench/installed/apps/frappe/frappe/app.py", line 57, in application
    response = frappe.handler.handle()
  File "/home/frappe/frappe-bench/installed/apps/frappe/frappe/handler.py", line 22, in handle
    data = execute_cmd(cmd)
  File "/home/frappe/frappe-bench/installed/apps/frappe/frappe/handler.py", line 53, in execute_cmd
    return frappe.call(method, **frappe.form_dict)
  File "/home/frappe/frappe-bench/installed/apps/frappe/frappe/__init__.py", line 922, in call
    return fn(*args, **newargs)
  File "/home/frappe/frappe-bench/installed/apps/erpnext/erpnext/accounts/doctype/account/chart_of_accounts/chart_of_accounts.py", line 108, in get_charts_for_country
    if (fname.startswith(country_code) or fname.startswith(country)) and fname.endswith(".json"):
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 19: ordinal not in range(128)