Increase request timeout and max latency to 1500ms

For high-latency connections, 1000ms was too aggressive and caused
false unreachable readings. Bump to 1500ms and add a 1500 tick to
the Y-axis.

src/main.js

@@ -8,9 +8,9 @@ import "./styles.css";
 const CONFIG = Object.freeze({
     updateInterval: 2000,
     historyDuration: 300,
-    requestTimeout: 1000,
-    maxLatency: 1000,
-    yAxisTicks: [0, 250, 500, 750, 1000],
+    requestTimeout: 1500,
+    maxLatency: 1500,
+    yAxisTicks: [0, 250, 500, 750, 1000, 1500],
     xAxisTicks: [0, 60, 120, 180, 240, 300],
     canvasHeight: 80,
     get maxHistoryPoints() {