Minor fix for access level of packet data

Source/Managed/ENet.cs

@@ -214,7 +214,7 @@ namespace ENet {
 			}
 		}
 
-		internal IntPtr Data {
+		public IntPtr Data {
 			get {
 				CheckCreated();
 
@@ -794,4 +794,4 @@ namespace ENet {
 		[DllImport(nativeLibrary, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern void enet_peer_reset(IntPtr peer);
 	}
-}
+}