net: disable IRQ when data is being enqueued

- This prevents broken json to be sent out due to IRQ

src/net/net.rs

@@ -246,6 +246,7 @@ impl ServerHandle {
     pub fn send(&mut self, buffer: &mut [u8], num_bytes: usize, socket_handles: SocketHandle) {
         let socket = self.socket_set.get_mut::<Socket>(socket_handles);
         if num_bytes > 0 {
+            cortex_m::interrupt::free(|_| {
                 match socket.send_slice(&buffer[..num_bytes]) {
                     Ok(_) => {
                         info!("Enqueued {} bytes.", num_bytes);
@@ -254,6 +255,7 @@ impl ServerHandle {
                         info!("Bytes cannot be sent. Error: {:?}", err)
                     }
                 };
+            });
         }
     }