only enable rcmgr by default in full nodes

opt-in with envvar for other nodes, as there are still some issues
with markets related protocols

node/modules/lp2p/rcmgr.go

@@ -27,8 +27,10 @@ import (
 
 func ResourceManager(connMgrHi uint) func(lc fx.Lifecycle, repo repo.LockedRepo) (network.ResourceManager, error) {
 	return func(lc fx.Lifecycle, repo repo.LockedRepo) (network.ResourceManager, error) {
+		isFullNode := repo.RepoType().Type() == "FullNode"
 		envvar := os.Getenv("LOTUS_RCMGR")
-		if envvar == "0" {
+		if (isFullNode && envvar == "0") || // enable by default for full nodes
+			(!isFullNode && envvar != "1") { // otherwise, opt-in with envvar
 			// this is enabled by default; specify LOTUS_RCMGR=0 to disable
 			log.Info("libp2p resource manager is disabled")
 			return network.NullResourceManager, nil