Follow the staging payment server to its new address

morph/grid/testing/grid.nix

@@ -9,7 +9,7 @@ import ../../lib/make-grid.nix {
     sshUsers = import ./users.nix;
   in {
     "payments" = import ../../lib/make-issuer.nix ({
-      publicIPv4 = "18.197.42.120";
+      publicIPv4 = "18.194.183.13";
       inherit sshUsers;
       hardware = ../../lib/issuer-aws.nix;
       stateVersion = "19.03";