CPP11 — Move recently added text to correct place

Summary: The recently addded fourth bullet on page 15-18 "For value types that have
an RMI: rep id, ORBs must include at least the most derived rep id, in the
value type encoding." should be moved back to be a paragraph on page 15-15,
preceding the paragraph that starts "If the receiving context ...".

Its current placement is incorrect because this section (15.3.4.4)
describes chunking, and this bullet has nothing to do with chunking but
concerns how much type information needs to be specified in the encoding
(the subject of section 15.3.4.1).

To accept proposed change