Description of problem:
The default node selection logic does not properly distribute gear load. In a 13-node district, 2-3 nodes will remain ignored until other nodes fill up under the current logic.

Version-Release number of selected component (if applicable):
2.2

How reproducible:
Always

Steps to Reproduce:
1. Create an environment with at least 13 nodes (have not tested with <13, but may reproduce with less). Each node should be the same gear size.
2. Create a district and add all 13 nodes.
2. Create 100 applications.
3. Check gear distribution with `oo-admin-ctl-gears | wc -l` on each node

Actual results:
Several nodes will be ignored, with no applications created on them:

Gear counts:
  Node1: 8
  Node2: 9
  Node3: 9
  Node4: 9
  Node5: 9
  Node6: 9
  Node7: 9
  Node8: 8
  Node9: 0
  Node10: 0
  Node11: 10
  Node12: 8
  Node13: 12

Expected results:
All nodes have even (or close to even) gear counts:

  Node1: 8
  Node2: 8
  Node3: 8
  Node4: 8
  Node5: 8
  Node6: 8
  Node7: 8
  Node8: 8
  Node9: 7
  Node10: 7
  Node11: 7
  Node12: 7
  Node13: 8