Update Issue Tracker link in conjunction with uBO (#999)

* Update Issue Tracker in conjunction with uBO

* Update Issue tracker title and description

Update Issue tracker title and description in conjunction with uBO

src/_locales/en/messages.json

@@ -566,8 +566,8 @@
         "description": ""
     },
     "aboutIssues" : {
-        "message": "Bugs and issues",
+        "message": "Issue tracker",
-        "description": ""
+        "description": "Text for a link to official issue tracker"
     },
     "aboutContributors":{
         "message":"Contributors",

src/about.html

@@ -23,7 +23,7 @@ ul {
     <li><a href="https://github.com/gorhill/uMatrix/wiki"><span data-i18n="aboutDoc"></span></a><br>
     <li><span data-i18n="aboutPermissions"></span><br>
     <li><a href="https://github.com/gorhill/uMatrix" data-i18n="aboutCode"></a><br>
-    <li><a href="https://github.com/gorhill/uMatrix/issues" data-i18n="aboutIssues"></a><br>
+    <li><a href="https://github.com/uBlockOrigin/uMatrix-issues/issues" data-i18n="aboutIssues"></a><br>
     <li><span data-i18n="aboutContributors"></span>
         <ul>
             <li><span data-i18n="aboutCodeContributors"></span> <a href="https://github.com/gorhill/uMatrix/graphs/contributors">uMatrix, <a href="https://github.com/gorhill/httpswitchboard/graphs/contributors">HTTP Switchboard</a>