Difference in parsing `x.[y]` to `Expr`

Likely due to #325 we have the following difference:

```julia
julia> dump(parsestmt(Expr, "x.[y]"))
Expr
head: Symbol .
args: Array{Any}((2,))
1: Symbol x
2: QuoteNode
value: Expr
head: Symbol vect
args: Array{Any}((1,))
1: Symbol y

julia> dump(JuliaSyntax.fl_parse(Expr, "x.[y]"))
Expr
head: Symbol .
args: Array{Any}((2,))
1: Symbol x
2: Expr
head: Symbol quote
args: Array{Any}((1,))
1: Expr
head: Symbol vect
args: Array{Any}((1,))
1: Symbol y
```