{client,server}: hide innernet-server CIDR from selection menus

It's a special /32 CIDR that is un-interactable, so is only taking
up space.

Closes #63

shared/src/prompts.rs

@@ -77,6 +77,7 @@ pub fn add_cidr(cidrs: &[Cidr], request: &AddCidrOpts) -> Result<Option<CidrCont
 pub fn choose_cidr<'a>(cidrs: &'a [Cidr], text: &'static str) -> Result<&'a Cidr, Error> {
     let cidr_names: Vec<_> = cidrs
         .iter()
+        .filter(|cidr| cidr.name != "innernet-server")
         .map(|cidr| format!("{} ({})", &cidr.name, &cidr.cidr))
         .collect();
     let cidr_index = Select::with_theme(&*THEME)