add judge of nil value for ports and networkids

app/services/blockchains_service.rb

@@ -24,8 +24,8 @@ class BlockchainsService
     ports = []
     bcs = Blockchain.find_by_sql("select network_id, port from blockchains where user_id=#{user.id}")
     bcs.each do |bc|
-      network_ids << bc.network_id
-      ports << bc.port
+      network_ids << bc.network_id unless network_id == nil
+      ports << bc.port unless port == nil
     end
     Rails.logger.info(network_ids)
     Rails.logger.info(ports)