[#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/add.go

@@ -30,8 +30,6 @@ func initAddCmd() {
 	ff := addCmd.Flags()
 	ff.StringSlice(metaFlagKey, nil, "Meta pairs in the form of Key1=[0x]Value1,Key2=[0x]Value2")
 	ff.Uint64(parentIDFlagKey, 0, "Parent node ID")
-
-	_ = cobra.MarkFlagRequired(ff, commonflags.RPC)
 }
 
 func add(cmd *cobra.Command, _ []string) {