Backport commit 1f6750b53 from Emacs

Avoid treating number as an enum in the org manual
1f6750b53a872a5747dff92b8f61cfede0c5a6a6
Stefan Kangas
Fri Jun 24 19:18:50 2022 +0200

[km] This same change was sent to the Org list and applied to main in
     db3870bfc.

doc/org-manual.org

@@ -8544,8 +8544,8 @@ commands:
   Search for a regular expression in all agenda files and additionally
   in the files listed in ~org-agenda-text-search-extra-files~.  This
   uses the Emacs command ~multi-occur~.  A prefix argument can be used
-  to specify the number of context lines for each match, default is
-  1.
+  to specify the number of context lines for each match, the default
+  is 1.
 
 - {{{kbd(#)}}} ::