Revert "enhance: replaced str.startsWith with str.indexOf (JakeChampi…

…on#1404)"

This reverts commit a686358.

fetch.js

@@ -543,7 +543,7 @@ export function fetch(input, init) {
       }
       // This check if specifically for when a user fetches a file locally from the file system
       // Only if the status is out of a normal range
-      if (request.url.indexOf('file://') === 0 && (xhr.status < 200 || xhr.status > 599)) {
+      if (request.url.startsWith('file://') && (xhr.status < 200 || xhr.status > 599)) {
         options.status = 200;
       } else {
         options.status = xhr.status;