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/t/t4211/sha256/expect.beginning-of-file

@@ -1,43 +0,0 @@
-commit 62a40b38fa4f00800004aee81ef287b7201317594ebcb990f38cbe493b01d200
-Author: Thomas Rast <trast@student.ethz.ch>
-Date:   Thu Feb 28 10:47:40 2013 +0100
-
-    change at very beginning
-
-diff --git a/a.c b/a.c
---- a/a.c
-+++ b/a.c
-@@ -1,3 +1,4 @@
-+#include <unistd.h>
- #include <stdio.h>
- 
- long f(long x)
-
-commit ccf97b9878189c40a981da50b15713bb80a35755326320ec80900caf22ced46f
-Author: Thomas Rast <trast@student.ethz.ch>
-Date:   Thu Feb 28 10:45:16 2013 +0100
-
-    touch both functions
-
-diff --git a/a.c b/a.c
---- a/a.c
-+++ b/a.c
-@@ -1,3 +1,3 @@
- #include <stdio.h>
- 
--int f(int x)
-+long f(long x)
-
-commit 1dd7e9b2b1699324b53b341e728653b913bc192a14dfea168c5b51f2b3d03592
-Author: Thomas Rast <trast@student.ethz.ch>
-Date:   Thu Feb 28 10:44:48 2013 +0100
-
-    initial
-
-diff --git a/a.c b/a.c
---- /dev/null
-+++ b/a.c
-@@ -0,0 +1,3 @@
-+#include <stdio.h>
-+
-+int f(int x)