Do not rely od DataStore for all connected nodes

Now that we track all connected flow-capable nodes we do need to go and
read all nodes just to find them. Just look at which handlers are
currently created.

Change-Id: I1a33b53399d0de0e2cdbdbd90512a09933d127c8
Signed-off-by: Robert Varga <rovarga@cisco.com>
Merge "Do not rely od DataStore for all connected nodes"