[#1442] cli/tree: Allow to specify rpc-endpoint with config file

We have several ways to specify the `rpc-endpoint`: with a flag,
with a single config file or multiple files. Before, the `rpc-endpoint`
flag was marked as required. Because `cobra` checked the required flag
presence first, it prevented specifying `rpc-endpoint` with a config file.

Signed-off-by: Aleksey Savchuk <a.savchuk@yadro.com>

cmd/frostfs-cli/modules/tree/remove.go

@@ -29,8 +29,6 @@ func initRemoveCmd() {
 	ff.Uint64(nodeIDFlagKey, 0, "Node ID.")
 
 	_ = getSubtreeCmd.MarkFlagRequired(nodeIDFlagKey)
-
-	_ = cobra.MarkFlagRequired(ff, commonflags.RPC)
 }
 
 func remove(cmd *cobra.Command, _ []string) {