Private message publish has 10min delay if number of nodes connected is small

[operatornormal]

Following erratic behavior has been observed:

• If private message is posted, and node of the recipient is not currently on-line
• If there is only small number of nodes currently on-line in the network
  classified-ads will try to contact nodes belonging in the same DHT bucket where the message recipient resides and if node-number is small, it never catches any. After time-out of 10 minutes it gives up, and publishes the message to any node that is connected.

It is inconvinient for the user that needs to keep the program open for 10 minutes after posting a private message to ensure semi-instant delivery. Otherwise the private message will remain in publish-queue and be published next time the program is started but that may be much later ; after that delay content of the message may be already obsolete.