In version 1.0.x local development mode was integrated in the plugin. Starting from v1.1.x it is moved to another plugin as an add-on. Since v1.0 of hot code push plugin does some tweaks to the iOS project file to activate Swift support - after updating to v1.1.x you need to disable it.

The easiest way is to reinstall iOS platform:

cordova platform remove ios
cordova platform add ios

When platform is added - all project's plugins will be installed automatically.

Harder approach - remove Swift support manually. For that you need to open your iOS project in Xcode, and then do the following:

1. In the Build Settings set Embedded Content Contains Swift Code to NO.
2. In the project files find <YOUR_PROJECT_NAME>-Prefix.pch file, open it and remove #import <YOUR_PROJECT_NAME>-Swift.h. For example:

#ifdef __OBJC__
    #import "TestProject-Swift.h"
#endif

3. Build the project to check, if everything is fine.