allow removal of Damoose account

Signed-off-by: kernelkind <kernelkind@gmail.com>

crates/notedeck/src/account/cache.rs

@@ -6,6 +6,7 @@ use crate::{SingleUnkIdAction, UserAccount};
 pub struct AccountCache {
     selected: Pubkey,
     fallback: Pubkey,
+    fallback_account: UserAccount,
 
     // never empty at rest
     accounts: HashMap<Pubkey, UserAccount>,
@@ -16,12 +17,13 @@ impl AccountCache {
         let mut accounts = HashMap::with_capacity(1);
 
         let pk = fallback.key.pubkey;
-        accounts.insert(pk, fallback);
+        accounts.insert(pk, fallback.clone());
 
         (
             Self {
                 selected: pk,
                 fallback: pk,
+                fallback_account: fallback,
                 accounts,
             },
             SingleUnkIdAction::pubkey(pk),
@@ -49,13 +51,18 @@ impl AccountCache {
     }
 
     pub(super) fn remove(&mut self, pk: &Pubkey) -> Option<UserAccount> {
-        // fallback account should never be removed
-        if *pk == self.fallback {
+        if *pk == self.fallback && self.accounts.len() == 1 {
+            // no point in removing it since it'll just get re-added anyway
             return None;
         }
 
         let removed = self.accounts.remove(pk);
 
+        if self.accounts.is_empty() {
+            self.accounts
+                .insert(self.fallback, self.fallback_account.clone());
+        }
+
         if removed.is_some() && self.selected == *pk {
             // TODO(kernelkind): choose next better
             let (next, _) = self