Description of problem:
When try to create manifests with openstack platform, got panic:


Version-Release number of the following components:
Client Version: 4+ ./openshift-install create manifests --dir '/home/jenkins/workspace/Launch Environment Flexy/workdir/install-dir'

level=info msg="Credentials loaded from file \"/home/jenkins/workspace/Launch Environment Flexy/workdir/clouds.yaml.20200803-559-exrnuf\""

panic: runtime error: integer divide by zero

goroutine 1 [running]:
github.com/openshift/installer/pkg/asset/machines/openstack.Machines(0xc00180b900, 0x11, 0xc0009a7b00, 0xc000c9ca80, 0xc00185fb20, 0x17, 0xcf92a13, 0x6, 0xd037119, 0x18, ...)
	/go/src/github.com/openshift/installer/pkg/asset/machines/openstack/machines.go:55 +0xd21
github.com/openshift/installer/pkg/asset/machines.(*Master).Generate(0x161ec520, 0xc00180d410, 0xcfe4408, 0x12)
	/go/src/github.com/openshift/installer/pkg/asset/machines/master.go:241 +0x3b11
github.com/openshift/installer/pkg/asset/store.(*storeImpl).fetch(0xc000a2c2d0, 0xe79b5a0, 0x161ec520, 0x0, 0x0, 0x40a4f5, 0xba89ee0)
	/go/src/github.com/openshift/installer/pkg/asset/store/store.go:227 +0x7bf
github.com/openshift/installer/pkg/asset/store.(*storeImpl).Fetch(0xc000a2c2d0, 0xe79b5a0, 0x161ec520, 0x161a8d00, 0x4, 0x4, 0xf700000000000000, 0xed6b9713e)
	/go/src/github.com/openshift/installer/pkg/asset/store/store.go:77 +0x4b
main.runTargetCmd.func1(0x7ffe557a89bf, 0x44, 0xc00000dc20, 0xc000a2c0c0)
	/go/src/github.com/openshift/installer/cmd/openshift-install/create.go:172 +0x133
main.runTargetCmd.func2(0x161b45a0, 0xc00000da40, 0x0, 0x2)
	/go/src/github.com/openshift/installer/cmd/openshift-install/create.go:199 +0xb2
github.com/spf13/cobra.(*Command).execute(0x161b45a0, 0xc00000da00, 0x2, 0x2, 0x161b45a0, 0xc00000da00)
	/go/src/github.com/openshift/installer/vendor/github.com/spf13/cobra/command.go:844 +0x29d
github.com/spf13/cobra.(*Command).ExecuteC(0xc000918000, 0xc001181e58, 0x1, 0x1)
	/go/src/github.com/openshift/installer/vendor/github.com/spf13/cobra/command.go:945 +0x317
github.com/spf13/cobra.(*Command).Execute(...)
	/go/src/github.com/openshift/installer/vendor/github.com/spf13/cobra/command.go:885
main.installerMain()
	/go/src/github.com/openshift/installer/cmd/openshift-install/main.go:63 +0x2b3
main.main()
	/go/src/github.com/openshift/installer/cmd/openshift-install/main.go:43 +0xc6.6.0-202008011451.p0-9cc7d77
./openshift-install 4.6.0-0.nightly-2020-08-02-091622
built from commit 2f8b52e8e950cdb1f0575f7a58cb53d7166f2955
release image registry.svc.ci.openshift.org/ocp/release@sha256:a0cd5e461757e8c0d0f4e6563ffd716dca90e8ed2956bd6b1405223e74da057c

How reproducible:
Always

Steps to Reproduce:
1. Create manifests with openstack platform
2.
3.

Actual results:
Got panic

Expected results:
Should work well.

Additional info:
Please attach logs from ansible-playbook with the -vvv flag