Don't touch uninitialized storage for version safeguard

This prevents an edge case where PD would crash if starting before the
very first genesis. Not touching storage in that case will prevent nodes
running continuously from genesis from benefitting from the safeguard,
but an upgrade has already happened on mainnet, and so we don't care
about not having the safeguard in this case.

crates/core/app/src/app_version/component.rs

@@ -110,6 +110,11 @@ async fn write_app_version_safeguard<S: StateWrite>(s: &mut S, x: u64) -> anyhow
 /// This will also result in the current app version being stored, so that future
 /// calls to this function will be checked against this state.
 pub async fn assert_latest_app_version(s: Storage) -> anyhow::Result<()> {
+    // If the storage is not initialized, avoid touching it at all,
+    // to avoid complaints about it already being initialized before the first genesis.
+    if s.latest_version() == u64::MAX {
+        return Ok(());
+    }
     let mut delta = StateDelta::new(s.latest_snapshot());
     let found = read_app_version_safeguard(&delta).await?;
     check_version(CheckContext::Running, APP_VERSION, found)?;