Add forgotten '||true' to prevent 'make install-man' from returning an error...

Add forgotten '||true' to prevent 'make install-man' from returning an error if rsync is not present on the platform

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@531875 13f79535-47bb-0310-9956-ffa450edef68