IOError: [Errno 24] Too many open files

[Ryan J Ollos]

Discussed in ​trac-users:l7xsbecKhVA/jpIkzWExCgAJ, errors like the following were seen:

2016-06-28 20:40:23,400 Trac[main] ERROR: Internal Server Error: <RequestWithSession "GET '/ticket/3048'">, referrer '<obfuscated>'
Traceback (most recent call last):
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/web/main.py", line 562, in _dispatch_request
    dispatcher.dispatch(req)
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/web/main.py", line 249, in dispatch
    resp = chosen_handler.process_request(req)
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/ticket/web_ui.py", line 181, in process_request
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/ticket/web_ui.py", line 533, in _process_ticket_request
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/ticket/model.py", line 71, in __init__
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/ticket/api.py", line 281, in get_ticket_fields
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/util/translation.py", line 202, in gettext
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/util/translation.py", line 182, in isactive
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/util/translation.py", line 148, in activate
  File "<obfuscated>/private/pve/local/lib/python2.7/site-packages/babel/support.py", line 562, in load
IOError: [Errno 24] Too many open files: '<obfuscated>/private/pve/local/lib/python2.7/site-packages/trac/locale/en_US/LC_MESSAGES/messages.mo'

The attached patch has been proposed to fix the issue.