Fix for --enable-complex
Fix for --enable-complex

For our templated code to compile properly even in the degenerate
cases, our DecrementRank degenerate case needs to be something that
can be multiplied by and assigned to from Numbers.

Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh