Solve validation errors and add an additional category.

--- qtagconvert.desktop
+++ qtagconvert.desktop
@@ -1,14 +1,12 @@
 [Desktop Entry]
 Type=Application
-Version=2.0.0
-Encoding=UTF-8
+Version=1.0
 Name=QTagConvert
 Name[ru]=QTagConvert
 GenericName=Tag Editor
 GenericName[ru]=Редактор тегов
 Exec=qtagconvert
-Comment=QTagConvert
 Icon=qtagconvert
 MimeType=audio/mpeg;audio/x-mp3;
 Terminal=false
-Categories=AudioVideo;
+Categories=Qt;AudioVideo;