Setup protocol after ready has already fired

lib/browser/api/protocol.js

@@ -9,9 +9,15 @@ exports.registerStandardSchemes = function (schemes) {
   registerStandardSchemes(schemes)
 }
 
-app.once('ready', function () {
+const setupProtocol = function () {
   let protocol = session.defaultSession.protocol
   for (let method in protocol) {
     exports[method] = protocol[method].bind(protocol)
   }
-})
+}
+
+if (app.isReady()) {
+  setupProtocol()
+} else {
+  app.once('ready', setupProtocol)
+}