Change rabbitmq-server log file names to not use the '@' character.

Due to problems downloading files having a '@' in their path from
logs.openstack.org, we need to rename the rabbitmq-server logs so
that they do not contain the '@' character.

Change-Id: Ic9099ef4166a76d3f7bffd44a6f15fddfcf45cd4
Related-Change: I6daaf0475b1dab6bcd56c4d838f4600271d6a8be
Merge "Change rabbitmq-server log file names to not use the '@' character."