Remove a clutch that causes bad error messages and seems useless.

It causes bad error messages in the case were the parametric node is undefined.

e.g., the equation

  S=if(M[n-1]) then (entiernat<<n>>(M)-puiss<<n+1>>(2)) else entiernat<<n>>(M);

raises "Error: Bad number of (static) arguments: 0 expected, and 1 provided."
when entiernat is undefined

It seems useless because no test is broken. The comment mention node
parameters that themselves have parameters. But it is the case for
test/should_work/Gyroscope2.lus, and it is still working.