add new flag 'ssh-host' to flux bootstrap git

Add a new flag `ssh-host` to the flux bootstrap git command which
enables users to specify the hostname of the Git SSH server in case its
different than the Git HTTP(s) server. Azure Devops is an example, with
its HTTPS server hosted at dev.azure.com and its SSH server hosted at
ssh.dev.azure.com.

Signed-off-by: Sanskar Jaiswal <jaiswalsanskar078@gmail.com>

cmd/flux/bootstrap_git.go

@@ -72,6 +72,7 @@ type gitFlags struct {
 	password            string
 	silent              bool
 	insecureHttpAllowed bool
+	sshHost             string
 }
 
 const (
@@ -88,6 +89,7 @@ func init() {
 	bootstrapGitCmd.Flags().StringVarP(&gitArgs.password, "password", "p", "", "basic authentication password")
 	bootstrapGitCmd.Flags().BoolVarP(&gitArgs.silent, "silent", "s", false, "assumes the deploy key is already setup, skips confirmation")
 	bootstrapGitCmd.Flags().BoolVar(&gitArgs.insecureHttpAllowed, "allow-insecure-http", false, "allows http git url connections")
+	bootstrapGitCmd.Flags().StringVar(&gitArgs.sshHost, "ssh-host", "", "Git SSH server host (to be used if the SSH server host is different than the HTTP(s) host)")
 
 	bootstrapCmd.AddCommand(bootstrapGitCmd)
 }
@@ -229,6 +231,9 @@ func bootstrapGitCmdRun(cmd *cobra.Command, args []string) error {
 
 		// Configure last as it depends on the config above.
 		secretOpts.SSHHostname = repositoryURL.Host
+		if gitArgs.sshHost != "" {
+			secretOpts.SSHHostname = gitArgs.sshHost
+		}
 	}
 
 	// Sync manifest config