Few minor changes
Added a method to check if the server is running

NodeLookupReceiver
Only use the server if it's running
Problem: If we had a cached content and a node asks for a content, we would return this content
Problem 2: If we had a cached content and we're one of the K-closest we can't know if to return it or not?

Solution: Add a field to also know if we're one of the K-Closest nodes; only return a content if the node is
Bug Found
- Before we were checking for updated content even if the owner is the localNode - no need to do that really!