Fix 'Next' button disabled in Wizard Options

The 'Next' button in the Wizard Options interface is disabled after an
API call fails, and does not automatically re-enable even after the API
call eventually succeeds.

src/components/smart/WizardPage/WizardPage.tsx

@@ -542,6 +542,8 @@ class WizardPage extends React.Component<Props, State> {
       return;
     }
     try {
+      this.setState({ nextButtonDisabled: false });
+
       await providerStore.getOptionsValues({
         optionsType: type,
         endpointId: endpoint.id,