vector.hpp: fix The -> This.
vector.hpp: fix The -> This.

kaskr/CppAD,wegamekinglc/CppAD,kaskr/CppAD,kaskr/CppAD,wegamekinglc/CppAD,kaskr/CppAD,wegamekinglc/CppAD,wegamekinglc/CppAD,wegamekinglc/CppAD,kaskr/CppAD