Remove duplicate _() in the error path
    
    When running IPA in locale de_DE.UTF-8 I got an internal error:
    
    jochen@freeipa1:~$ ipa server-del freeipa4.example.org
    Removing freeipa4.example.org from replication topology, please wait...
    ipa: ERROR: Ein interner Fehler ist aufgetreten
    
    This is not the complete messages. Using en_US.UTF-8 would be ok.
    In the httpd error_log:
    
    ] ipa: ERROR: non-public: TypeError: unhashable type: 'Gettext'
    ] Traceback (most recent call last):
    ]   File "/usr/lib/python3.10/site-packags/ipaserver/rpcserver.py", line 407, in wsgi_execute
    ]     result = command(*args, **options)
    ]   File "/usr/lib/python3.10/site-packages/ipalib/frontend.py", line 471, in __call__
    ]     return self.__do_call(*args, **options)
    ]   File "/usr/lib/python3.10/site-packages/ipalib/frontend.py", line 499, in __do_call
    ]     ret = self.run(*args, **options)
    ]   File "/usr/lib/python3.10/site-packages/ipalib/frontend.py", line 821, in run
    ]     return self.execute(*args, **options)
    ]   File "/usr/lib/python3.10/site-packages/ipaserver/plugins/baseldap.py", line 1686, in execute]     return self.execute(*args, **options)
    ]   File "/usr/lib/python3.10/site-packages/ipaserver/plugins/baseldap.py", line 1686, in execute
    ]     delete_entry(pkey)
    ]   File "/usr/lib/python3.10/site-packages/ipaserver/plugins/baseldap.py", line 1637, in delete_entry
    ]     dn = callback(self, ldap, dn, *nkeys, **options)
    ]   File "/usr/lib/python3.10/site-packages/ipaserver/plugins/server.py", line 755, in pre_callback
    ]     self._ensure_last_of_role(
    ] File
    "/usr/lib/python3.10/site-packages/ipaserver/plugins/server.py", line
    520, in _ensure_last_of_role
    ]     handler(
    ]   File "/usr/lib/python3.10/site-packages/ipaserver/plugins/server.py", line 482, in handler
    ]     raise errors.ServerRemovalError(reason=_(msg))
    ]   File "/usr/lib/python3.10/site-packages/ipalib/errors.py", line 269, in __init__
    ]     messages.process_message_arguments(self, format, message, **kw)
    ]   File "/usr/lib/python3.10/site-packages/ipalib/messages.py", line 55, in process_message_arguments
    ]     kw[key] = unicode(value)
    ]   File "/usr/lib/python3.10/site-packages/ipalib/text.py", line 296, in __str__
    ]     return unicode(self.as_unicode())
    ]   File "/usr/lib/python3.10/site-packages/ipalib/text.py", line 293, in as_unicode
    ]     return t.gettext(self.msg)
    ]   File "/usr/lib64/python3.10/gettext.py", line 498, in gettext
    ]     tmsg = self._catalog.get(message, missing)
    ] TypeError: unhashable type: 'Gettext'
    ] ipa: INFO: [jsonserver_session] admin@EXAMPLE.ORG:
    server_del/1(['freeipa4.example.org'], version='2.245'): InternalError
    
    Alexander suggested to remove _() in local handler() function in
    _ensure_last_of_role():
    
                else:
                    raise errors.ServerRemovalError(reason=_(msg))
    
    Looks like all the callers give already gettext-enabled message (wrapped
    with _() already).
    
    At least for my case I now get a complete error message.
    
    Fixes: https://pagure.io/freeipa/issue/9046
    Signed-off-by: Jochen Kellner <jochen@jochen.org>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>