revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/Documentation/git-svn.txt

@@ -677,8 +677,7 @@ config key: svn.authorsProg
 -s<strategy>::
 --strategy=<strategy>::
 -p::
---rebase-merges::
---preserve-merges (DEPRECATED)::
+--preserve-merges::
 	These are only used with the 'dcommit' and 'rebase' commands.
 +
 Passed directly to 'git rebase' when using 'dcommit' if a
@@ -770,11 +769,11 @@ option for (hopefully) obvious reasons.
 +
 This option is NOT recommended as it makes it difficult to track down
 old references to SVN revision numbers in existing documentation, bug
-reports, and archives.  If you plan to eventually migrate from SVN to
-Git and are certain about dropping SVN history, consider
-https://github.com/newren/git-filter-repo[git-filter-repo] instead.
-filter-repo also allows reformatting of metadata for ease-of-reading
-and rewriting authorship info for non-"svn.authorsFile" users.
+reports and archives.  If you plan to eventually migrate from SVN to Git
+and are certain about dropping SVN history, consider
+linkgit:git-filter-branch[1] instead.  filter-branch also allows
+reformatting of metadata for ease-of-reading and rewriting authorship
+info for non-"svn.authorsFile" users.
 
 svn.useSvmProps::
 svn-remote.<name>.useSvmProps::