OSX/CI: kio-extras builds to fail on branch master

[Marko Käning]

On Linux kio-extras seems to build fine, but it doesn’t on OSX:

---

[92%] Building C object nfs/CMakeFiles/kio_nfs.dir/rpc_nfs3_prot_xdr.c.o
/Users/marko/WC/KDECI-builds/kio-extras/nfs/rpc_nfs3_prot_xdr.c:13:8: error: implicit declaration of function 'xdr_u_quad_t' [-Werror,-Wimplicit-function-declaration]
         if (!xdr_u_quad_t (xdrs, objp))
              ^
/Users/marko/WC/KDECI-builds/kio-extras/nfs/rpc_nfs3_prot_xdr.c:11:20: warning: unused variable 'buf' [-Wunused-variable]
        register int32_t *buf;
                          ^
/Users/marko/WC/KDECI-builds/kio-extras/nfs/rpc_nfs3_prot_xdr.c:23:8: error: implicit declaration of function 'xdr_quad_t' [-Werror,-Wimplicit-function-declaration]
         if (!xdr_quad_t (xdrs, objp))
              ^
/Users/marko/WC/KDECI-builds/kio-extras/nfs/rpc_nfs3_prot_xdr.c:23:8: note: did you mean 'xdr_u_quad_t'?
/Users/marko/WC/KDECI-builds/kio-extras/nfs/rpc_nfs3_prot_xdr.c:13:8: note: 'xdr_u_quad_t' declared here
         if (!xdr_u_quad_t (xdrs, objp))
              ^