gateways: only force apinger status if running

(cherry picked from commit 89d73f69)

src/etc/inc/gwlb.inc

@@ -393,16 +393,16 @@ function return_gateways_status($byname = false)
 {
     global $config;
 
-    $apingerstatus = array();
+    $status = array();
 
-    /* Always get the latest status from apinger */
+    if (isvalidpid('/var/run/apinger.pid')) {
+        /* always get the latest status from apinger */
         killbypid('/var/run/apinger.pid', 'USR1');
+
         /* we may read the wrong file here as it's async: */
         if (file_exists('/var/run/apinger.status')) {
             $apingerstatus = file('/var/run/apinger.status');
-    }
 
-    $status = array();
             foreach ($apingerstatus as $line) {
                 $info = explode('|', $line);
                 if ($byname == false) {
@@ -419,6 +419,8 @@ function return_gateways_status($byname = false)
                 $status[$target]['loss'] = sprintf('%0.1f %%', empty($info[7]) ? 0.0 : round($info[7], 1));
                 $status[$target]['status'] = trim($info[8]);
             }
+        }
+    }
 
     /* tack on any gateways that have monitoring disabled
      * or are down, which could cause gateway groups to fail */