cli: fix typo

Release note: None

pkg/cli/start.go

@@ -437,7 +437,7 @@ func runStart(cmd *cobra.Command, args []string, disableReplication bool) error
 	// First things first: if the user wants background processing,
 	// relinquish the terminal ASAP by forking and exiting.
 	//
-	// If executing in the backround, the function returns ok == true in
+	// If executing in the background, the function returns ok == true in
 	// the parent process (regardless of err) and the parent exits at
 	// this point.
 	if ok, err := maybeRerunBackground(); ok {