Fix kwin runtime config reload for vmsilo
Allow overriding allowed wayland protocols for VMs through ~/.config/kwinrc:
```
kwriteconfig6 --file kwinrc --group Vmsilo --type stringlist --key AllowedProtocols "wl_shm,wl_compositor,wl_subcompositor,xdg_wm_base,wl_data_device_manager,zxdg_output_manager_v1,zwp_primary_selection_device_manager_v1,gtk_primary_selection_device_manager,wl_seat,wl_output,org_kde_kwin_server_decoration_manager,zxdg_decoration_manager_v1,zwp_relative_pointer_manager_v1,zwp_pointer_constraints_v1,wp_viewporter,wp_cursor_shape_manager_v1,wp_fractional_scale_manager_v1,wp_single_pixel_buffer_manager_v1,wp_alpha_modifier_v1,wp_color_representation_manager_v1,wp_color_manager_v1,frog_color_management_factory_v1,wp_fifo_manager_v1,wp_presentation,zwp_linux_dmabuf_v1"
```