Avoid errors when bytes is undefined (quasarframework#1579)

* Avoid errors when

* Avoid errors when bytes in undefined

Author: insign

src/utils/format.js

@@ -3,7 +3,7 @@ const units = ['B', 'kB', 'MB', 'GB', 'TB', 'PB']
 export function humanStorageSize (bytes) {
   let u = 0
 
-  while (Math.abs(bytes) >= 1024 && u < units.length - 1) {
+  while (parseInt(bytes) >= 1024 && u < units.length - 1) {
     bytes /= 1024
     ++u
   }