zcashparams verify promisified func

main.js

@@ -387,6 +387,7 @@ function createWindow(status) {
 		mainWindow.appSessionHash = appSessionHash;
 		mainWindow.assetChainPorts = require('./routes/ports.js');
 		mainWindow.zcashParamsExist = _zcashParamsExist;
+		mainWindow.zcashParamsExistPromise = shepherd.zcashParamsExistPromise;
 		mainWindow.agamaIcon = agamaIcon;
 		mainWindow.testLocation = shepherd.testLocation;
 		mainWindow.kmdMainPassiveMode = shepherd.kmdMainPassiveMode;

routes/shepherd/downloadZcparams.js

@@ -54,6 +54,13 @@ module.exports = (shepherd) => {
     return _checkList;
   }
 
+  shepherd.zcashParamsExistPromise = () => {
+    return new shepherd.Promise((resolve, reject) => {
+      const _verify = shepherd.zcashParamsExist();
+      resolve(_verify);
+    });
+  };
+
   /*
    *  Update bins
    *  type: