Backport - Fix #730 - Improve browser detection: DuckDuckGo

(cherry picked from commit e87c794fd9)

src/ua-parser.js

@@ -243,6 +243,8 @@
             /(heytap|ovi)browser\/([\d\.]+)/i,                                  // Heytap/Ovi
             /(weibo)__([\d\.]+)/i                                               // Weibo
             ], [NAME, VERSION], [
+            /\bddg\/([\w\.]+)/i                                                 // DuckDuckGo
+            ], [VERSION, [NAME, 'DuckDuckGo']], [
             /(?:\buc? ?browser|(?:juc.+)ucweb)[\/ ]?([\w\.]+)/i                 // UCBrowser
             ], [VERSION, [NAME, 'UC'+BROWSER]], [
             /microm.+\bqbcore\/([\w\.]+)/i,                                     // WeChat Desktop for Windows Built-in Browser