[libcxx] [test] Fix URLs in comments and make them HTTPS. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@310156 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/function.objects/func.not_fn/not_fn.pass.cpp

@@ -587,7 +587,7 @@ void call_operator_noexcept_test()
 }
 
 void test_lwg2767() {
-    // See http://wg21.link/LWG2767
+    // See https://cplusplus.github.io/LWG/lwg-defects.html#2767
     struct Abstract { virtual void f() const = 0; };
     struct Derived : public Abstract { void f() const {} };
     struct F { bool operator()(Abstract&&) { return false; } };