use event length instead of strlen() when dropping something into a terminal

the data member of Elm_Selection_Data may not be nul terminated, so
any string operation on this is liable to crash

src/bin/termio.c

@@ -5664,7 +5664,7 @@ _smart_cb_drop(void *data, Evas_Object *o EINA_UNUSED, Elm_Selection_Data *ev)
           evas_object_smart_callback_call(obj, "popup", ev->data);
      }
    else
-     termpty_write(sd->pty, ev->data, strlen(ev->data));
+     termpty_write(sd->pty, ev->data, ev->len);
    return EINA_TRUE;
 }
 #endif