snippets providers

`browser.newtabpage.activity-stream.asrouter.providers.snippets`

These (which landed in FF64 with snippets above) are not in the user.js, so why bother with the snippet one
- `browser.newtabpage.activity-stream.asrouter.providers.cfr`
- `browser.newtabpage.activity-stream.asrouter.providers.onboarding`

also these aren't in the user.js
- `browser.newtabpage.activity-stream.asrouter.providers.cfr-fxa`
- `browser.newtabpage.activity-stream.asrouter.providers.message-groups`
- `browser.newtabpage.activity-stream.asrouter.providers.messaging-experiments`
- `browser.newtabpage.activity-stream.asrouter.providers.whats-new-panel`

There are no privacy concerns here. At the end of the day, what Firefox connects to and sends is E2EE and only used locally in non-web content: and you have other prefs and a UI to disable them from being displayed

scratchpad-scripts/arkenfox-clear-removed.js

@@ -1,7 +1,7 @@
 /***
  This will reset the preferences that have been removed completely from the arkenfox user.js.
 
- Last updated: 02-Nov-2020
+ Last updated: 30-Dec-2020
 
  For instructions see:
  https://github.com/arkenfox/user.js/wiki/3.1-Resetting-Inactive-Prefs-[Scripts]
@@ -230,6 +230,7 @@
     'security.ssl3.dhe_rsa_aes_128_sha',
     'security.ssl3.dhe_rsa_aes_256_sha',
     /* 84-beta */
+    'browser.newtabpage.activity-stream.asrouter.providers.snippets',
     'layout.css.visited_links_enabled',
     /* reset parrot: check your open about:config after running the script */
     '_user.js.parrot'