Fix "Never stacks closing parens" test failure

[lgastako]

  1) Imports.format Never stacks closing parens
       Falsifiable (after 2 tests and 4 shrinks): 
       False
       False
       0
       0
       Import {qualified = True, importedModule = "g", asClause = Just "", hiding = True, members = Just [OpMember ")" [""]]}