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/t9810-git-p4-rcs.sh

@@ -294,6 +294,7 @@ test_expect_success 'cope with rcs keyword file deletion' '
 		echo "\$Revision\$" >kwdelfile.c &&
 		p4 add -t ktext kwdelfile.c &&
 		p4 submit -d "Add file to be deleted" &&
+		cat kwdelfile.c &&
 		grep 1 kwdelfile.c
 	) &&
 	git p4 clone --dest="$git" //depot &&