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/INSTALL

@@ -109,15 +109,15 @@ Issues of note:
 
  - Git is reasonably self-sufficient, but does depend on a few external
    programs and libraries.  Git can be used without most of them by adding
-   the appropriate "NO_<LIBRARY>=YesPlease" to the make command line or
+   the approriate "NO_<LIBRARY>=YesPlease" to the make command line or
    config.mak file.
 
 	- "zlib", the compression library. Git won't build without it.
 
 	- "ssh" is used to push and pull over the net.
 
-	- A POSIX-compliant shell is required to run some scripts needed
-	  for everyday use (e.g. "bisect", "request-pull").
+	- A POSIX-compliant shell is required to run many scripts needed
+	  for everyday use (e.g. "bisect", "pull").
 
 	- "Perl" version 5.8 or later is needed to use some of the
 	  features (e.g. preparing a partial commit using "git add -i/-p",