Add missing dependency in SparseSholesky header
(transplanted from a3c07164632c3fceea8b94ae5e2be73f2d72af61)

--HG--
branch : 3.1
extra : transplant_source : %A3%C0qdc%2C%3F%CE%EA%8B%94%AE%5E%2B%E7%3F-r%AFa