Log: cib: Drop the message serverity now that the cause is well understood

t0:  node1 starts
t1:  node3 "everyone make change ABC"
t2:  everyone receives the ABC message
t3:  node1 to node2 "please send me your cib, i'm out of date"
t4:  node4 "everyone make change DEF"
t5:  node2 to node1 "here you go"
t6:  everyone receives the DEF message
t7:  everyone receives the t6 message
t8:  node1 - dude, this is out of date "current num_updates is greater
than the replacement"

Or in english, it happens when new commands arrive between the sync
request being sent and the response being sent out.