SILKY_ANALYZE_QUERIES=True causes unexpected data updates

Hi! First of all thanks for creating this library!

I have a case where I increment an integer like this: MyModel.objects.filter(pk=101).update(counter=F('counter')+1)

When using silk with SILKY_ANALYZE_QUERIES=True - my counter is incremented twice for every sql statement I make. This is probably not a bug, but I suggest to put a big warning in the docs, so that people use this setting with caution.