Update UptimeKuma.php (#830)

change an === operator to the !== operator.

Author: mikley

UptimeKuma/UptimeKuma.php

@@ -62,7 +62,7 @@ public function livestats()
                 continue;
             }
 
-            if (strpos($line, 'monitor_status') === 0) {
+            if (strpos($line, 'monitor_status') !== 0) {
                 // If the line is a metric but not a monitor we can ignore it
                 continue;
             }