Backport 1363832:

RPM packaging: Remove the BuildArch from the manual package, this forces
the target to "noarch" for all packages and breaks the build on CentOS5.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1364086 13f79535-47bb-0310-9956-ffa450edef68