Update api.php

Consume JSON output of chronometer.sh

Relies on [this pull](https://github.com/jacobsalmela/pi-hole/pull/193) being merged.

api.php

@@ -1,15 +1,3 @@
-<?php
-    $domains_being_blocked = exec("wc -l /etc/pihole/gravity.list | awk '{print $1}'");
-    $dns_queries_today = exec("cat /var/log/pihole.log | awk '/query/ {print $6}' | wc -l");
-    $ads_blocked_today = exec("cat /var/log/pihole.log | awk '/\/etc\/pihole\/gravity.list/ && !/address/ {print $6}' | wc -l");
-    $ads_percentage_today = $ads_blocked_today / $dns_queries_today * 100;
-    $arr = array(
-        'domains_being_blocked' => $domains_being_blocked,
-        'dns_queries_today' => $dns_queries_today,
-        'ads_blocked_today' => $ads_blocked_today,
-        'ads_percentage_today' => $ads_percentage_today
-    );
-
-    header('Content-type: application/json');
-    echo json_encode($arr);
+<?php 
+    echo exec("/usr/local/bin/chronometer.sh -j"); 
 ?>