fix newly introduced clippy lints

fix newly introduced clippy lints

backend: pack next record LSN into the encoded message (neondatabase#33)

This field only needs to be read after the batch is decoded,
so we can move into the body to get more efficient encoding.

tokio-postgres v0.7.12

postgres v0.19.9

postgres-types v0.2.8

postgres-derive v0.4.6

tokio-postgres v0.7.11

postgres v0.19.8

postgres-types v0.2.7