remove double negation in --help (#2405)

Co-authored-by: ChristopherHX <[email protected]>

cmd/root.go

@@ -87,7 +87,7 @@ func Execute(ctx context.Context, version string) {
 	rootCmd.PersistentFlags().StringVarP(&input.containerArchitecture, "container-architecture", "", "", "Architecture which should be used to run containers, e.g.: linux/amd64. If not specified, will use host default architecture. Requires Docker server API Version 1.41+. Ignored on earlier Docker server platforms.")
 	rootCmd.PersistentFlags().StringVarP(&input.containerDaemonSocket, "container-daemon-socket", "", "", "URI to Docker Engine socket (e.g.: unix://~/.docker/run/docker.sock or - to disable bind mounting the socket)")
 	rootCmd.PersistentFlags().StringVarP(&input.containerOptions, "container-options", "", "", "Custom docker container options for the job container without an options property in the job definition")
-	rootCmd.PersistentFlags().StringVarP(&input.githubInstance, "github-instance", "", "github.com", "GitHub instance to use. Don't use this if you are not using GitHub Enterprise Server.")
+	rootCmd.PersistentFlags().StringVarP(&input.githubInstance, "github-instance", "", "github.com", "GitHub instance to use. Only use this when using GitHub Enterprise Server.")
 	rootCmd.PersistentFlags().StringVarP(&input.artifactServerPath, "artifact-server-path", "", "", "Defines the path where the artifact server stores uploads and retrieves downloads from. If not specified the artifact server will not start.")
 	rootCmd.PersistentFlags().StringVarP(&input.artifactServerAddr, "artifact-server-addr", "", common.GetOutboundIP().String(), "Defines the address to which the artifact server binds.")
 	rootCmd.PersistentFlags().StringVarP(&input.artifactServerPort, "artifact-server-port", "", "34567", "Defines the port where the artifact server listens.")