Fix .mp4 detection to video/mp4

Author: Kaliumhexacyanoferrat

Modules/Basics/CoreExtensions.cs

@@ -114,7 +114,7 @@ public static bool HasType(this IRequest request, params RequestMethod[] methods
             { "mk3d", ContentType.VideoMatroska3D },
             { "mj2", ContentType.VideoMJ2 },
             { "mpg", ContentType.VideoMpeg },
-            { "mp4", ContentType.AudioMp4 },
+            { "mp4", ContentType.VideoMP4 },
             { "mpeg", ContentType.VideoMpeg },
             { "mpv", ContentType.VideoMpv },
             { "mov", ContentType.VideoQuicktime },