setting default pubsub topic value and modifying log

waku/factory/external_config.nim

@@ -298,6 +298,7 @@ type WakuNodeConf* = object
 
     pubsubTopics* {.
       desc: "Default pubsub topic to subscribe to. Argument may be repeated.",
+      defaultValue: @["/waku/2/rs/0/0"],
       name: "pubsub-topic"
     .}: seq[string]
 

waku/factory/internal_config.nim

@@ -39,7 +39,7 @@ proc enrConfiguration*(
     if shardsOpt.isSome():
       shards = shardsOpt.get().shardIds
     else:
-      info "no pubsub topics specified or pubsubtopic is of type Named sharding "
+      info "no pubsub topics specified"
   # some shards configured
   else:
     shards = toSeq(conf.shards.mapIt(uint16(it)))