GPasteHistory: fix memory leak

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
GPasteHistory: fix bad memory access

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
Merge branch '3.0'

* 3.0:
  GPasteHistory: fix bad memory access
  GPasteHistory: fix memory leak