backport trunk r683280

mod_ssl: Use memmove instead of memcpy for overlapping buffers

Submitted by: jorton
Reviewed by: sf, trawick



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@1001762 13f79535-47bb-0310-9956-ffa450edef68