Description
DDG as default message still present even after removig DDG as a search engine in about:preferences#search

Environments
Windows 10

Tested with:
Firefox 78.0b5 , Firefox nightly 79.0a1 (june11)

**Steps **
Download latest Romanian Beta firefox build
Install addon https://addons.mozilla.org/en-US/firefox/addon/duckduckgo-for-firefox
enter about:preferences#search
notice the message "An extension, DuckDuckGo Privacy Essentials, has set your default search engine."
Scroll below, and delete duckduckgo from the list
Duckduck Go has been removed.
Noticed that now GOOGLE is your default, even with the addon still installed.

Actual Results
"An extension, DuckDuckGo Privacy Essentials, has set your default search engine." still shows up, even after restarting.
duckduckgo is not your default anymore and it goes to google default.

Expected Result
its kind of a grey area because the user still has the addon installed and chose to remove duckduckgo from the list of his engines.
Im not sure if google should be default or the DDG with new code should still be default even if user removed it from about:preferences and kept the addon installed.
so its complicated to decide what is the correct result, but differences show because of this.

There's two issues here. The main issue here is that we're not removing the notification when we change the default. Bug 1638888 is probably going to fix that.

I was wrong about the bugs here, this is actually a result of bug 1546652.

We no longer have that prompt in preferences.