Suggestion: Better RuntimeException message

[hamidpeywasti]

Hi, here "XMLWriter" class is needed to be enabled not only "libxml".

BaconQrCode/src/Renderer/Image/SvgImageBackEnd.php

Lines 35 to 37 in 510de6e

	if (! class_exists(XMLWriter::class)) {
	throw new RuntimeException('You need to install the libxml extension to use this back end');
	}

So, I think it's better to mention that 'You need to install the libxml extension and enable the XMLWriter class to use this back end'.

[Cris123m]

I recently spent several hours with this error, without knowing how to solve it, until I found this message, and I knew that I needed to enable xmlwriter.
Thank you.
And I also agree that this message should be updated.