manila.conf has "standard_extenstions" typo

Am getting the following error in /var/log/apache2/manila_error.log when restarting apache2:

  [Thu Mar 16 04:40:49.107752 2023] [wsgi:error] [pid 252468:tid 140664973539072] 2023-03-16 04:40:49.107 252468 WARNING manila.api.extensions [-] Failed to load extension manila.api.contrib.standard_extenstions: Class standard_extenstions cannot be found (['Traceback (most recent call last):\\n', ' File "/usr/lib/python3/dist-packages/oslo_utils/importutils.py", line 32, in import_class\\n return getattr(sys.modules[mod_str], class_str)\\n', "AttributeError: module 'manila.api.contrib' has no attribute 'standard_extenstions'\\n"]).\x1b[00m

And, indeed, when I look at the manila.conf I see:

  osapi_share_extension = manila.api.contrib.standard_extenstions

The typo (extra t in "extensions") is in all the charm templates for manila.conf.

This doesn't seem to interfere with manila's operation but an error is an error and it should be fixed.