Redundant arguments

[ctchou]

One line 286 of:

https://github.com/leanprover-community/mathematics_in_lean/blob/master/MIL/C08_Groups_and_Rings/S01_Groups.lean

the arguments "[Fintype G] (h : Disjoint H K) (h' : Nat.card G = Nat.card H * Nat.card K)" of iso₁ are unnecessary because they have already been declared on line 278-279 using "variable".