Remove extra title

Author: jondy

src/webui/index-zh.html

@@ -8,8 +8,6 @@
   <meta name="Keywords" content="python, obfuscate, obfuscation, obfuscator" />
   <title>Pyarmor - Obfuscate Python Scripts</title>
 
-  <title>Pyarmor</title>
-
   <link rel="stylesheet" href="css/bootstrap.min.css" type="text/css" />
   <style type="text/css">
     .toolbar {