fix: Blind-signing gate is bypassed for single-byte calldata 0x00 transactions (#983)

Co-authored-by: Cerberus Merlin <merlin@cerberus.security>

Author: Donjon-Cerberus

src/features/sign_tx/eth_ustream.c

@@ -315,10 +315,6 @@ static bool process_data(txContext_t *context) {
     if (context->currentFieldPos < context->currentFieldLength) {
         uint32_t copySize =
             MIN(context->commandLength, context->currentFieldLength - context->currentFieldPos);
-        // If there is no data, set dataPresent to false.
-        if (copySize == 1 && *context->workBuffer == 0x00) {
-            context->content->dataPresent = false;
-        }
 
         if ((context->currentFieldPos == 0) && (copySize >= 4)) {
             // Consider the 4 1st bytes are the selector