gvfs: replace deprecated g_memmove by memmove

* g_memmove was deprecated ib glib-2.0 2.40
* opening a remote connection created by gigolo with thunar failed with:
  | thunar: symbol lookup error: /usr/lib/modules/libgvfsdbus.so: undefined symbol: g_memmove
* further tests showed that browsing in windows networks is fixed now

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>