fix: allow starting insecure man server (#1297)

crates/cdk-mintd/src/lib.rs

@@ -886,12 +886,17 @@ async fn start_services_with_shutdown(
 
                 let tls_dir = rpc_settings.tls_dir_path.unwrap_or(work_dir.join("tls"));
 
-                if !tls_dir.exists() {
-                    tracing::error!("TLS directory does not exist: {}", tls_dir.display());
-                    bail!("Cannot start RPC server: TLS directory does not exist");
-                }
+                let tls_dir = if tls_dir.exists() {
+                    Some(tls_dir)
+                } else {
+                    tracing::warn!(
+                        "TLS directory does not exist: {}. Starting RPC server in INSECURE mode without TLS encryption",
+                        tls_dir.display()
+                    );
+                    None
+                };
 
-                mint_rpc.start(Some(tls_dir)).await?;
+                mint_rpc.start(tls_dir).await?;
 
                 rpc_server = Some(mint_rpc);