Don't attempt to upload if no servers were given

src/main.rs

@@ -107,6 +107,12 @@ fn main() -> Result<(), String> {
       no_confirm,
       file_name,
     } => {
+      
+      if servers.is_empty() {
+        println!("Please provide some servers to upload to. See --help");
+        return Ok(())
+      }
+      
       start_ssh_agent()?;
 
       let file_name_info =