Merge pull request #221 from mrdeep1/issue-197

coap_io.c,net.c: Fix head of node queue re-transmit timeouts

src/coap_io.c

@@ -1102,7 +1102,6 @@ coap_write(coap_context_t *ctx,
   nextpdu = coap_peek_next(ctx);
 
   while (nextpdu && now >= ctx->sendqueue_basetime && nextpdu->t <= now - ctx->sendqueue_basetime) {
-    nextpdu->t = 0;
     coap_retransmit(ctx, coap_pop_next(ctx));
     nextpdu = coap_peek_next(ctx);
   }

src/net.c

@@ -2349,7 +2349,6 @@ static void coap_retransmittimer_execute(void *arg) {
       break;
     } else {
       elapsed -= nextinqueue->t;
-      nextinqueue->t = 0;
       coap_retransmit(ctx, coap_pop_next(ctx));
       nextinqueue = coap_peek_next(ctx);
     }