Update CoAP to 4.0.11

This PR implement https://tools.ietf.org/html/rfc7959#section-2.5
"The error code 4.13 (Request Entity Too Large) can be returned at any
time by a server that does not currently have the resources to store
blocks for a block-wise request payload transfer that it would intend
to implement in an atomic fashion. (Note that a 4.13 response to a
request that does not employ Block1 is a hint for the client to try
sending Block1, and a 4.13 response with a smaller SZX in its Block1
Option than requested is a hint to try a smaller SZX.)

Author: Jani Suonpera

features/FEATURE_COMMON_PAL/mbed-coap/module.json

@@ -1,6 +1,6 @@
 {
   "name": "mbed-coap",
-  "version": "4.0.10",
+  "version": "4.0.11",
   "description": "COAP library",
   "keywords": [
     "coap",

features/FEATURE_COMMON_PAL/mbed-coap/source/sn_coap_protocol.c

@@ -1756,6 +1756,15 @@ static sn_coap_hdr_s *sn_coap_handle_blockwise_message(struct coap_s *handle, sn
 
                 /* Check block size */
                 block_temp = (src_coap_blockwise_ack_msg_ptr->options_list_ptr->block1 & 0x07);
+                uint16_t block_size = 1u << (block_temp + 4);
+                if (block_size >  handle->sn_coap_block_data_size) {
+                     // Include maximum size that stack can handle into response
+                     tr_error("sn_coap_handle_blockwise_message - (recv block1) COAP_MSG_CODE_RESPONSE_REQUEST_ENTITY_TOO_LARGE!");
+                     src_coap_blockwise_ack_msg_ptr->msg_code = COAP_MSG_CODE_RESPONSE_REQUEST_ENTITY_TOO_LARGE;
+                     src_coap_blockwise_ack_msg_ptr->options_list_ptr->size1 = handle->sn_coap_block_data_size;
+                     sn_coap_protocol_linked_list_blockwise_payload_remove_oldest(handle);
+                }
+
                 if (block_temp > sn_coap_convert_block_size(handle->sn_coap_block_data_size)) {
                     src_coap_blockwise_ack_msg_ptr->options_list_ptr->block1 &= 0xFFFFF8;
                     src_coap_blockwise_ack_msg_ptr->options_list_ptr->block1 |= sn_coap_convert_block_size(handle->sn_coap_block_data_size);