message: Remove redundant MakeUCharSpan wrappers
diff: @@ -1309,7 +1309,7 @@ static RPCHelpMan combinepsbt()
  CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
  ssTx << merged_psbt;
  - return EncodeBase64(MakeUCharSpan(ssTx));
  + return EncodeBase64(ssTx);
  },
  };
  }
  @@ -1443,7 +1443,7 @@ static RPCHelpMan createpsbt()
  CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
  ssTx << psbtx;
  - return EncodeBase64(MakeUCharSpan(ssTx));
  + return EncodeBase64(ssTx);
  },
  };
  }
  @@ -1512,7 +1512,7 @@ static RPCHelpMan converttopsbt()
  CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
  ssTx << psbtx;
  - return EncodeBase64(MakeUCharSpan(ssTx));
  + return EncodeBase64(ssTx);
  },
  };
  }
  @@ -1603,7 +1603,7 @@ static RPCHelpMan utxoupdatepsbt()
  CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
  ssTx << psbtx;
  - return EncodeBase64(MakeUCharSpan(ssTx));
  + return EncodeBase64(ssTx);
  },
  };
  }
  @@ -1699,7 +1699,7 @@ static RPCHelpMan joinpsbts()
  CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
  ssTx << shuffled_psbt;
  - return EncodeBase64(MakeUCharSpan(ssTx));
  + return EncodeBase64(ssTx);
  },
  };
  }
  