send-pack: remove remote reference limit

When build a pack for a push we query the remote copy for existant
heads.  These are used to prune unnecessary objects from the pack.
As we receive the remote references in get_remote_heads() we validate
the reference names via check_ref() which includes a length check;
rejecting those >45 characters in size.

We appear to be able to handle reference names upto MAXPATHLEN in
size.  Relax the limit out to that size.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
---
diff --git a/connect.c b/connect.c
index 4422a0d..0a51e78 100644
--- a/connect.c
+++ b/connect.c
@@ -17,7 +17,7 @@ static int check_ref(const char *name, i
 	if (!flags)
 		return 1;
 
-	if (len > 45 || memcmp(name, "refs/", 5))
+	if (len > MAXPATHLEN || memcmp(name, "refs/", 5))
 		return 0;
 
 	/* Skip the "refs/" part */