Always accept --output argument.
Always accept --output argument.

Even if no RandR support exists, allow the option. The user will be
informed that the output was not found sooner or later anyway.

This also fixes the issue that the option parsing would still
continue, leading to a screwed user experience.

Signed-off-by: Tobias Stoeckmann <059b8b880f8441509ec8a65b50b4c6ae74ebea76@stoeckmann.org>

stoeckmann/xwallpaper,stoeckmann/xwallpaper