Fix syntax in test_load_balancer_basics._check_load_balancing

The set == {} syntax is invalid in python 2.6.

Note that even though the test is currently being skipped,
it's interpreted before the skip is executed so this fails
regardless of the skip decorator.

Closes-Bug: #1277951

Change-Id: Ic64622604a717db33555784cfe265e6af3e6dea7
1 file changed