fix(useragent): 修复双子星APP判断错误

plugins/user-agent.js

@@ -7,7 +7,7 @@ export default function (c, i) {
       return /Android/i.test(navigator.userAgent);
     },
     get isSzx() {
-      return /Szx/i.test(navigator.userAgent);
+      return /Szx\//i.test(navigator.userAgent);
     },
     get isMobile() {
       return /Mobile/i.test(navigator.userAgent);
@@ -19,7 +19,7 @@ export default function (c, i) {
       return /miniProgram/i.test(navigator.userAgent);
     },
     get isSzxBrowser() {
-      return /SZXBrowser/i.test(navigator.userAgent);
+      return /SZXBrowser\//i.test(navigator.userAgent);
     },
   });
 }