reduce compilation time (thanks @rafaqz)

Author: Alexander-Barth

src/cfvariable.jl

@@ -570,7 +570,7 @@ Base.Array(v::AbstractVariable{T,N}) where {T,N} = v[ntuple(i -> :, Val(N))...]
 function Base.Array(v::AbstractVariable{T,0}) where {T}
     a = Array{T,0}(undef,size(v))
     # only a single element to load
-    a .= v
+    a[] = v[]
     return a
 end