comments: fix misuses of "nor"

Signed-off-by: Justin Lebar <jlebar@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/sha1_file.c b/sha1_file.c
index 6e8c05d..b79efe4 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -787,7 +787,7 @@
  * contain the same set of objects as an existing one.  In that case
  * the resulting file might be different even if its name would be the
  * same.  It is best to close any reference to the old pack before it is
- * replaced on disk.  Of course no index pointers nor windows for given pack
+ * replaced on disk.  Of course no index pointers or windows for given pack
  * must subsist at this point.  If ever objects from this pack are requested
  * again, the new version of the pack will be reinitialized through
  * reprepare_packed_git().