fix: 🐛 compat: don't use ?. for compat with older node.js

lib/index.js

@@ -29,7 +29,7 @@ let plugins = {}
 function loadplugin(pluginname, pluginpath) {
     try {
         plugins[pluginname] = require(pluginpath)
-        plugins[pluginname]?.load(cfg)
+        plugins[pluginname].load(cfg)
     } catch (error) {
         if (error.code == 'MODULE_NOT_FOUND') {
             console.warn('plugin not used:', pluginpath)
@@ -44,7 +44,7 @@ function unloadplugin(pluginname, pluginpath) {
     const plugin = require.resolve(pluginpath)
     try {
         if (plugin && require.cache[plugin]) {
-            require.cache[plugin].exports?.unload()
+            require.cache[plugin].exports.unload()
             delete plugins[pluginname]
             delete require.cache[plugin]
         }