Fixed getFormattedTime sometimes returning (NaN:NaN) (#643)

* Fixed getFormattedTime sometimes returning (NaN:NaN)

getFormattedTime() with nothing passed into it and a couple other edge cases returned (NaN:NaN). This is a problem since on a slow machine getFormattedTime get called without anything passed into it around the time the computer is fetching the timing data. I haven't found the exact spot / place it is called wrongly, but this should fix it. I've have a slow machine so it's really been bugging me seeing (NaN:NaN) for a couple seconds before the page fully loads. Hopefully this should fix it.

src/utils.ts

@@ -376,6 +376,9 @@ class Utils {
             //add a zero
             minutesDisplay = "0" + minutesDisplay;
         }
+        if (isNaN(hours) || isNaN(minutes)) {
+            return null;
+        }
 
         const formatted = (hours ? hours + ":" : "") + minutesDisplay + ":" + secondsDisplay;