src: fix small memory leak

PR-URL: #28452
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/node_contextify.cc

@@ -260,11 +260,14 @@ void ContextifyContext::MakeContext(const FunctionCallbackInfo<Value>& args) {
   if (try_catch.HasCaught()) {
     if (!try_catch.HasTerminated())
       try_catch.ReThrow();
+    delete context;
     return;
   }
 
-  if (context->context().IsEmpty())
+  if (context->context().IsEmpty()) {
+    delete context;
     return;
+  }
 
   sandbox->SetPrivate(
       env->context(),