bip-0375: say the version byte belongs to the identifier, not to the field

"The PSBT_OUT_SP_V0_INFO should be serialized as a zero byte for the
version, followed by the 33 bytes of the scan key and then 33 bytes for
the spend key" names the field, and the field is 66 bytes: its table
entry is "<33 byte scan key> <33 byte spend key>", the test vectors carry
66, and the validator refuses anything else.

The sentence is in the Unique Identification section and was added with
it, so what it describes is the output script that stands in for a silent
payment output when building the unsigned transaction that identifies the
psbt -- 67 bytes there, and nothing about the field. Read as the field's
own serialization it contradicts the table, which is how it first read
here.

Only the wording changes.

bip-0375.mediawiki

@@ -147,7 +147,7 @@ If only PSBT_OUT_SCRIPT is present for an output, then the output is not being s
 ===Unique Identification===
 
 Silent payment capable PSBTs can be uniquely identified the same way as PSBTv2s, except when including silent payment outputs. If an output contains the PSBT_OUT_SP_V0_INFO field, it must use that field instead of PSBT_OUT_SCRIPT as the output script when creating the unsigned transaction used for unique identification.<ref name="why_use_sp_info_field"> ''' Why use PSBT_OUT_SP_V0_INFO when serializing for a unique identifier?''' Since the same silent payment capable PSBT is valid whether or not a PSBT_OUT_SCRIPT is included in an output that has PSBT_OUT_SP_V0_INFO set, using the PSBT_OUT_SCRIPT if present for the unique identifier will cause malleability. The identifier will be different depending on whether PSBT_OUT_SCRIPT is present, so always using PSBT_OUT_SP_V0_INFO if it exists makes sure the PSBT is always identified uniquely.</ref>
-The PSBT_OUT_SP_V0_INFO should be serialized as a zero byte for the version, followed by the 33 bytes of the scan key and then 33 bytes for the spend key.
+In that unsigned transaction, each silent payment output's script is serialized as a 0x00 version byte, the 33-byte scan key, then the 33-byte spend key.
 
 
 ==Roles==