Fix errors caused by changes made to ThrowableProxy

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1595563 13f79535-47bb-0310-9956-ffa450edef68
Loop to force a rollover then allow time for it to complete

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk@1595564 13f79535-47bb-0310-9956-ffa450edef68