fix: config file parse errors not reported as missing DATABASE_URL

crates/config/tests/loader_test.rs

@@ -377,3 +377,15 @@ fn secure_cookies_and_image_conversion_accept_true_only() {
         Ok(())
     });
 }
+
+#[test]
+fn malformed_config_file_reports_the_file_not_a_missing_database_url() {
+    Jail::expect_with(|jail| {
+        jail_with(jail, &[]);
+        jail.create_file("config.toml", "[server\nport = = 1\n")?;
+        let err = load().expect_err("config.toml is malformed");
+        assert!(matches!(err, ConfigError::Unreadable(_)), "{err}");
+        assert!(!err.to_string().contains("DATABASE_URL"), "{err}");
+        Ok(())
+    });
+}