Simple Ad Plugin and Regular WordPress and A little problem of notification

Hello,

I was mistook for a multi-site wordpress plugin (simple ad plugin) to be compatible with regular wordpress installation, and after installing it, I had to remove as it stopped my regular wordpress website from working. After doing rm -rf pluginname inside wp-content/plugins/, I keep seeing this notification from wpmudev.org:
Please install the latest version of our free Update Notifications plugin which helps you stay up-to-date with the most stable, secure versions of WPMU DEV themes and plugins. More information »

How do I remove that? Have rm -rf wp-content/plugins/pluginname actually removed the plugin or I have to dig into database? If I have to dig into database, what do I need to look for to completely remove the plugin for simple ad plugin?