fix(settings): give the add-host button the tooltip its neighbour has

The + and the ⋯ sit side by side above the Hosts list at the same size
and weight; only the ⋯ named itself on hover. It now says "New host",
the same words the form it opens puts in its title.

src/ui/settings.rs

@@ -1835,6 +1835,7 @@ impl Tty7App {
                                     .icon(Icon::new(IconName::Plus))
                                     .ghost()
                                     .small()
+                                    .tooltip(t(L10nKey::SettingsNewHost))
                                     .on_click(cx.listener(|this, _, window, cx| {
                                         this.add_new_profile(window, cx)
                                     })),