panic: reading /etc/services
Similar to #9, when the `/etc/services` file is not formatted correctly, this project will panic trying to parse the file.
## History
Issue #9 was filed a year ago and linked to a non-English issue. Putting it through [google translate](https://github-com.translate.goog/Mrs4s/go-cqhttp/discussions/1024?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp) reveals that in the users `/etc/services` file there is the following entry at the end:
```
privoxy 8118
```
Which does not follow the typical format of `port/protocol` (e.g. `21/tcp`).
I am a maintainer of [telegraf](https://github.com/influxdata/telegraf/) and recently received a [similar issue](https://github.com/influxdata/telegraf/issues/12084), where the user had the same line in their `/etc/services` file.
## Steps to reproduce
1. Update `/etc/services` file to include `privoxy 8118`
2. Create the following `main.go`:
```go
package main
import _ "modernc.org/libc"
func main() {}
```
3. The following `go.mod`:
```go
module test
go 1.19
require modernc.org/libc v1.21.1
```
4. Run `go run main.go`
5. Remember to revert your change to `/etc/services`
## Logs
```
panic: runtime error: index out of range [1] with length 1
goroutine 1 [running]:
modernc.org/libc/honnef.co/go/netdb.init.0()
/go/pkg/mod/modernc.org/libc@v1.20.3/honnef.co/go/netdb/netdb.go:760 +0x4c8
```
issue