Adapt to math-comp/math-comp#1456

Author: proux01

theories/planar/hmap_ops.v

@@ -1,4 +1,5 @@
-From mathcomp Require Import all_ssreflect ring.
+From mathcomp Require Import all_ssreflect.
+From mathcomp.algebra_tactics Require Import ring.
 From GraphTheory Require Import edone preliminaries bij.
 From fourcolor Require Import hypermap geometry cfmap jordan color coloring combinatorial4ct.
 From fourcolor Require Import walkup.