--server gdb requires a crossover uart to be present

[zyp]

Executing wishbone-tool with --server gdb without a crossover uart present results in an error. The following code snippet from config.rs seems to be missing the if-statement for ServerKind::Terminal or whatever it is called:

            if server_kind.contains(&ServerKind::GDB) {
                // You asked for --server gdb but no vexriscv jtag interfaces is found in the csr.csv file it should complain.
                if !register_mapping.contains_key("vexriscv_debug") {
                    return Err(ConfigError::InvalidConfig(
                        "GDB specified but no vexriscv address present in csv file".to_owned(),
                    ));
                }
                // You asked for --server terminal but no uart is found in the csr.csv file it should complain.
                if !(register_mapping.contains_key("uart_xover_rxtx")
                    && register_mapping.contains_key("uart_xover_rxempty")
                    && register_mapping.contains_key("uart_xover_ev_pending"))
                {
                    return Err(ConfigError::InvalidConfig(
                        "Terminal specified, but no xover uart addresses present in csv file"
                            .to_owned(),
                    ));
                }
            }

[xobs]

Good catch. I think this is a big enough issue to warrant a new minor release.