Correct `Params` instances for `lookup` and `singletonM`.

We always use Leibniz keys (nat for list, Countable for maps), so the Params should be one higher.

In fact, for singletonM and insert we already use the correct number for Params.

stdpp/base.v

@@ -1210,7 +1210,7 @@ on maps. In the file [fin_maps] we will axiomatize finite maps.
 The function look up [m !! k] should yield the element at key [k] in [m]. *)
 Class Lookup (K A M : Type) := lookup: K → M → option A.
 Global Hint Mode Lookup - - ! : typeclass_instances.
-Global Instance: Params (@lookup) 4 := {}.
+Global Instance: Params (@lookup) 5 := {}.
 Notation "m !! i" := (lookup i m) (at level 20) : stdpp_scope.
 Notation "(!!)" := lookup (only parsing) : stdpp_scope.
 Notation "( m !!.)" := (λ i, m !! i) (only parsing) : stdpp_scope.
@@ -1221,7 +1221,7 @@ Global Arguments lookup _ _ _ _ !_ !_ / : simpl nomatch, assert.
 of the partial [lookup] function. *)
 Class LookupTotal (K A M : Type) := lookup_total : K → M → A.
 Global Hint Mode LookupTotal - - ! : typeclass_instances.
-Global Instance: Params (@lookup_total) 4 := {}.
+Global Instance: Params (@lookup_total) 5 := {}.
 Notation "m !!! i" := (lookup_total i m) (at level 20) : stdpp_scope.
 Notation "(!!!)" := lookup_total (only parsing) : stdpp_scope.
 Notation "( m !!!.)" := (λ i, m !!! i) (only parsing) : stdpp_scope.