fix null check

src/public/index.html

@@ -3935,7 +3935,7 @@
 
         // get position precision in meters
         const positionPrecisionInMeters = getPositionPrecisionInMeters(positionPrecision);
-        if(positionPrecision == null){
+        if(positionPrecisionInMeters == null){
             return "?";
         }