Fix MOST_RECENT_FETCHER reporting after channel changes, a=chris

diff --git a/src/executables/QueueServer.php b/src/executables/QueueServer.php
index 0f86d5add..c10ed9e94 100755
--- a/src/executables/QueueServer.php
+++ b/src/executables/QueueServer.php
@@ -1673,10 +1673,13 @@ class QueueServer implements CrawlConstants, Join
      */
     public function updateMostRecentFetcher()
     {
-        $robot_table_name = C\CRAWL_DIR . "/" . self::robot_table_name;
+        $robot_table_name = C\CRAWL_DIR . "/" . $this->channel . "-" .
+            self::robot_table_name;
+        L\crawlLog("Updating most recent fetcher...");
         if (file_exists($robot_table_name)) {
             $robot_table = unserialize(file_get_contents($robot_table_name));
             if (!is_array($robot_table)) {
+                L\crawlLog("... couldn't unserialize robot table correctly.");
                 return;
             }
             $recent = 0 ;
@@ -1686,6 +1689,10 @@ class QueueServer implements CrawlConstants, Join
                     $recent = $robot_data[2];
                 }
             }
+            L\crawlLog("... Most recent fetcher was: " .
+                $this->most_recent_fetcher);
+        } else {
+            L\crawlLog("... couldn't find robot table.");
         }
     }
     /**