[clang-tidy][docs] Fix wrong url in DontModifyStdNamespaceCheck

It was probably a copy-paste mistake.
The check was added as `cert-dcl58-cpp`, so the doc should point there.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D121373

clang-tools-extra/clang-tidy/cert/DontModifyStdNamespaceCheck.h

@@ -19,7 +19,7 @@ namespace cert {
 /// This check warns for such modifications.
 ///
 /// For the user-facing documentation see:
-/// http://clang.llvm.org/extra/clang-tidy/checks/cert-msc53-cpp.html
+/// https://clang.llvm.org/extra/clang-tidy/checks/cert-dcl58-cpp.html
 class DontModifyStdNamespaceCheck : public ClangTidyCheck {
 public:
   DontModifyStdNamespaceCheck(StringRef Name, ClangTidyContext *Context)