Add one more level of parenthesis because the (long) cast has to

apply to the complete expression or GCC still complains with:

proxy_cache.c:334: warning: long int format, different type arg (arg 6)
proxy_cache.c:365: warning: long int format, different type arg (arg 6)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@81681 13f79535-47bb-0310-9956-ffa450edef68