In order to detect if a barcode scanner is being used, we detect the delay between keypresses. The value is hardcoded to 55 ms. However, in the case of a bluetooth scanner, this delay is often not enough, resulting in an incorrect capture of the barcode. We add the config parameter `barcode.max_time_between_keys_in_ms` which allows the user to fine tune this delay for his hardware. opw-806398