Updated example for Con.1

The original example was good, but it used a reference where the point
of Con.1 is about declaring objects themselves const

CppCoreGuidelines.md

@@ -13975,11 +13975,9 @@ Prevents accidental or hard-to-notice change of value.
 
 ##### Example
 
-    for (const string& s : c) cout << s << '\n';    // just reading: const
+    for (const int i : c) cout << i << '\n';    // just reading: const
 
-    for (string& s : c) cout << s << '\n';    // BAD: just reading
-
-    for (string& s : c) cin >> s;  // needs to write: non-const
+    for (int i : c) cout << i << '\n';          // BAD: just reading
 
 ##### Exception