fix(ws_transport): Fix crash when reading

When parsing WS framing protocol integer promotion would cause
invalid values to be read. Acting upon these values would eventually
cause a crash

Fixes esp-protocols#645

components/tcp_transport/transport_ws.c

@@ -504,7 +504,7 @@ static int ws_read_header(esp_transport_handle_t t, char *buffer, int len, int t
             ESP_LOGE(TAG, "Error read data");
             return rlen;
         }
-        payload_len = data_ptr[0] << 8 | data_ptr[1];
+        payload_len = (uint8_t)data_ptr[0] << 8 | (uint8_t)data_ptr[1];
     } else if (payload_len == 127) {
         // headerLen += 8;
         header = 8;
@@ -517,7 +517,7 @@ static int ws_read_header(esp_transport_handle_t t, char *buffer, int len, int t
             // really too big!
             payload_len = 0xFFFFFFFF;
         } else {
-            payload_len = data_ptr[4] << 24 | data_ptr[5] << 16 | data_ptr[6] << 8 | data_ptr[7];
+            payload_len = (uint8_t)data_ptr[4] << 24 | (uint8_t)data_ptr[5] << 16 | (uint8_t)data_ptr[6] << 8 | data_ptr[7];
         }
     }