Make advancing date on server testing-only

src/client_lib.rs

@@ -279,7 +279,8 @@ pub async fn blockage_migration(
     cred
 }
 
-// Advance days on server (ONLY FOR TESTING)
+#[cfg(test)]
+// Advance days on server
 pub async fn advance_days(net: &dyn Networking, days: u16) -> u32 {
     let resp = net
         .request(