fix: clarify available recovery paths wording

The previous wording could be misleading for recovery paths that
had already been available since many blocks ago.

For the user, it's enough to know that the path is available, i.e.
a spend on this recovery path can be created and broadcast.

liana-gui/src/app/view/recovery.rs

@@ -48,8 +48,13 @@ pub fn recovery<'a>(
                     Column::new()
                         .spacing(20)
                         .push(text(format!(
-                            "{} recovery paths will be available at the next block, select one:",
-                            recovery_paths.len()
+                            "{} recovery path{} available:",
+                            recovery_paths.len(),
+                            if recovery_paths.len() > 1 {
+                                "s are"
+                            } else {
+                                " is"
+                            },
                         )))
                         .push(Column::with_children(recovery_paths).spacing(20)),
                 )