added missing backtick in git-apply.txt

Signed-off-by: Danijel Tasov <dt@korn.shell.la>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-apply.txt

@@ -147,7 +147,7 @@ discouraged.
 	considered whitespace errors.
 +
 By default, the command outputs warning messages but applies the patch.
-When `git-apply is used for statistics and not applying a
+When `git-apply` is used for statistics and not applying a
 patch, it defaults to `nowarn`.
 +
 You can use different `<action>` to control this