Revert "add double force"

This reverts commit 6fac203d86d6df5f803a8d93db6bc07b86d66eeb.

Fix was applied to an autogenerated file,
it needs to be applied to the builtin help of the borg code.

docs/usage/prune.rst.inc

@@ -21,7 +21,7 @@ borg prune
     +-----------------------------------------------------------------------------+---------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+
     |                                                                             | ``-n``, ``--dry-run``                 | do not change repository                                                                                                                               |
     +-----------------------------------------------------------------------------+---------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+
-    |                                                                             | ``--force``                           | force pruning of corrupted archives, use ``--force --force`` in case ``--force`` does not work.                                                        |
+    |                                                                             | ``--force``                           | force pruning of corrupted archives                                                                                                                    |
     +-----------------------------------------------------------------------------+---------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+
     |                                                                             | ``-s``, ``--stats``                   | print statistics for the deleted archive                                                                                                               |
     +-----------------------------------------------------------------------------+---------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+