Add MimeType for ogv

Author: mythz

src/ServiceStack.Text/HttpUtils.cs

@@ -1174,6 +1174,9 @@ public static string GetMimeType(string fileNameOrExt)
                 case "webm":
                     return "video/" + fileExt;
 
+                case "ogv":
+                    return "video/ogg";
+
                 case "rtf":
                     return "application/" + fileExt;