Fix VPATH build of RQUOTA support.
Fix VPATH build of RQUOTA support.

Some rpcgen derive #include "..." paths from the infile argument.
This will be off for VPATH builds, as the generated rquota_xdr.c
code will look in $(srcdir), but we'll generate the rquota.h file in
$(builddir). Play safe and copy rquota.x to $(builddir) first.

This fixes the build on openSUSE 11.1.

damoxc/dovecot,damoxc/dovecot,damoxc/dovecot,damoxc/dovecot,damoxc/dovecot