Add bottom pagination in search subscribers page (#831)

I noticed that in the Campaign listings there is bottom pagination already but I didn't see any when using the Search subscribers.  I think it will be useful to add there also and it seems like a small change.

Author: arius28

public_html/lists/admin/inc/interfacelib.php

@@ -455,6 +455,9 @@ public function display($add_index = 0, $class = '')
         foreach ($this->elements as $element) {
             $html .= $this->listingElement($element);
         }
+	if (!empty($this->insideNav)) {
+            $html .= sprintf('<tr><td colspan="%d">%s</td></tr>', count($this->columns) + 1, $this->insideNav);
+        }
         $html .= $this->listingEnd();
 
         if ($this->usePanel) {