Merge pull request #2254 from ethereum/modileHide

fix modal dialog for provider

src/app/tabs/runTab/settings.js

@@ -178,7 +178,8 @@ class SettingsUI {
     selectExEnv.addEventListener('change', (event) => {
       let context = selectExEnv.options[selectExEnv.selectedIndex].value
       this.settings.changeExecutionContext(context, () => {
-        modalDialogCustom.confirm('External node request', 'Are you sure you want to connect to an ethereum node?', () => {
+        const modal = modalDialogCustom.confirm('External node request', 'Are you sure you want to connect to an ethereum node?', () => {
+          modal.hide()
           modalDialogCustom.prompt('External node request', 'Web3 Provider Endpoint', 'http://localhost:8545', (target) => {
             this.settings.setProviderFromEndpoint(target, context, (alertMsg) => {
               if (alertMsg) {