when the connection is cut the result seems to be undefined rather than an error, treating as retry fixes #557

Author: corevo

packages/selenium-ide/src/neo/IO/SideeX/ext-command.js

@@ -245,6 +245,9 @@ export default class ExtCommand {
         { frameId: top ? 0 : frameId }
       )
       .then(r => {
+        if (!r) {
+          throw new Error('result is undefined')
+        }
         return r
       })
       .catch(error => {