add curly braces to a single-line if block example in PEP 7 (#225)

pep-0007.txt

@@ -127,8 +127,9 @@ Code lay-out
 
       if (type->tp_dictoffset != 0 && base->tp_dictoffset == 0 &&
           type->tp_dictoffset == b_size &&
-          (size_t)t_size == b_size + sizeof(PyObject *))
+          (size_t)t_size == b_size + sizeof(PyObject *)) {
           return 0; /* "Forgive" adding a __dict__ only */
+      }
 
 * Put blank lines around functions, structure definitions, and major
   sections inside functions.