Issue #1621236 by andypost: Follow up to check on db_table_exists().

plugins/views_plugin_display_block.inc

@@ -208,7 +208,7 @@ function update_block_bid($name, $old_delta, $delta) {
     }
 
     // Maybe people don't have block module installed, so let's skip this.
-    if (module_exists('block')) {
+    if (db_table_exists('block')) {
       db_update('block')
         ->fields(array('delta' => $delta))
         ->condition('delta', $old_delta)