Move log statement to expose actually info_cache value

When debugging an info_cache issue I noticed the logs  display:

"Updating cache with info: None update_instance_cache_with_nw_info"

Though we are not actually updating the info_cache with None as if
nw_info is not isinstance(NetworkInfo we fetch the latest nw_info
from neturon. This patch just moves the log statement so the actual
value is exposed.

Change-Id: I3a74191c31a053682bb2558c59228025ceb0cf28
Closes-bug: 1292298
Merge "Move log statement to expose actually info_cache value"