Improving how last_sync is updated, a=chris

diff --git a/bin/mirror.php b/bin/mirror.php
index 1d1ca806b..ba95a3b66 100644
--- a/bin/mirror.php
+++ b/bin/mirror.php
@@ -230,6 +230,9 @@ class Mirror implements CrawlConstants
                 $this->start_sync = $time;
                 $this->sync_schedule = $info[self::DATA];
                 unset($info[self::DATA]);
+            } else if(isset($info[self::STATUS]) &&
+                $info[self::STATUS] == self::NO_DATA_STATE) {
+                $this->last_sync = $time;
             }
         } else {
             $info[self::STATUS] = self::CONTINUE_STATE;