[intro.execution] Fix indentation of example code

Author: jensmaurer

source/intro.tex

@@ -1017,9 +1017,9 @@
   // full-expression is destruction of \tcode{s2} at end of block
 }
 struct B {
-      B(S = S(0));
-   };
-   B b[2] = { B(), B() };  // full-expression is the entire initialization
+  B(S = S(0));
+};
+B b[2] = { B(), B() };     // full-expression is the entire initialization
                            // including the destruction of temporaries
 \end{codeblock}
 \end{example}