Removed hello_world from Russion translation

shell/android/res/values-ru/strings.xml

 <resources>
 
     <string name="app_name">reicast</string>
-    <string name="hello_world">Hello world!</string>
     <string name="menu_settings">Настройки</string>
     <string name="title_activity_main">reicast</string>
     <string name="system_path">Системная папка (папка с dc_boot.bin/dc_flash.bin)</string>