fix: Can't close the app using Android phone (close quasarframework#1897)

Author: rstoenescu

package.json

@@ -1,6 +1,6 @@
 {
   "name": "quasar-framework",
-  "version": "0.15.10",
+  "version": "0.15.11",
   "description": "Build responsive websites, PWAs, hybrid mobile apps and Electron apps, all simultaneously using same codebase",
   "files": [
     "dist",

src/plugins/history.js

@@ -27,6 +27,9 @@ export default {
         if (this.__history.length) {
           this.__history.pop().handler()
         }
+        else if (window.location.hash === '#/') {
+          navigator.app.exitApp()
+        }
         else {
           window.history.back()
         }