`ParametrizedAmplitude` cannot be instantiated without shape

[goerz]

julia> using QuantumControl.PulseParametrizations: SquareParametrization, ParametrizedAmplitude
julia> a = ParametrizedAmplitude(t->1.0; parametrization=SquareParametrization())
ERROR: A ParametrizedAmplitude control must either be a vector of values or a callable

The cause is a typo in the code (control being confused with shape)