sendCustomizedApp() allows a noFinish setting

This will allow `interface.html`s like `fwupdate` to continue
making changes.

See espruino/BangleApps#3153

js/index.js

@@ -353,7 +353,7 @@ function handleCustomApp(appTemplate) {
 
         getInstalledApps()
           .then(()=>checkDependencies(app))
-          .then(()=>Comms.uploadApp(app,{device:device, language:LANGUAGE}))
+          .then(()=>Comms.uploadApp(app,{device:device, language:LANGUAGE, noFinish:msg.noFinish}))
           .then(()=>{
             Progress.hide({sticky:true});
             resolve();

lib/customize.js

@@ -58,11 +58,12 @@ Util.saveCSV(filename, csvData)                 // pop up a dialog to save a CSV
 Util.showModal(title)                           // show a modal screen over everything in this window
 Util.hideModal()                                // hide the modal from showModal
 */
-function sendCustomizedApp(app) {
+function sendCustomizedApp(app, noFinish) {
   console.log("<CUSTOM> sending app");
   window.postMessage({
     type : "app",
-    data : app
+    data : app,
+    noFinish
   });
 }