fix another typo in git-repository.5
diff --git a/got/git-repository.5 b/got/git-repository.5
index e66e35c..c3d8db9 100644
--- a/got/git-repository.5
+++ b/got/git-repository.5
@@ -53,7 +53,7 @@ A
.Em tag
object associates a user-defined label with another object, which is
typically a commit object.
-Tag objects also contains a tag message, as well as author and
+Tag objects also contain a tag message, as well as author and
timestamp information.
.El
.Pp