exit 44 if http 404 is returned

This will allow the fedora element to know that there was a http 404 so
it can retry.

Change-Id: I42100a175e42af1c53909508245695ac82204fc0

elements/cache-url/bin/cache-url

@@ -54,5 +54,9 @@ elif [ "$rcode" = "304" -o "$rcode" = "213" ] ; then
 else
     echo "Server returned an unexpected response code. [$rcode]"
     rm -f $tmp
+    # expose some error codes so the calling process might know what happened
+    if [ "$rcode" = "404" ] ; then
+        exit 44
+    fi
     exit 1
 fi