Add link to privacy policy to About pane

I was sure it was there already but it turns out
it was not. Now it is.

Related discussion:
- https://www.reddit.com/r/uBlockOrigin/comments/nklywj/does_ublock_origin_now_collect_personal_data/gzjwhe4/

src/_locales/en/messages.json

@@ -847,6 +847,10 @@
     "message": "Markdown",
     "description": "Label for radio-button to pick export text format"
   },
+  "aboutPrivacyPolicy": {
+    "message": "Privacy policy",
+    "description": "Link to privacy policy on GitHub (English)"
+  },
   "aboutChangelog": {
     "message": "Changelog",
     "description": ""

src/about.html

@@ -17,6 +17,7 @@
     <div class="liul">
         <div class="li">Copyright (c) Raymond Hill 2014-present</div>
     </div>
+    <div class="li"><a href="https://github.com/gorhill/uBlock/wiki/Privacy-policy" data-i18n="aboutPrivacyPolicy"></a></div>
     <div class="li"><a href="https://github.com/gorhill/uBlock/releases" data-i18n="aboutChangelog"></a></div>
     <div class="li"><a href="https://github.com/gorhill/uBlock/wiki" data-i18n="aboutWiki"></a></div>
     <div class="li"><a href="https://old.reddit.com/r/uBlockOrigin/" data-i18n="aboutSupport"></a></div>