A test for thinness of skin

I have a bit, in fact rather a lot, of a weakness for the works of P.G.Wodehouse, and having thoroughly enjoyed lately re-reading 'Psmith in the City' and 'Psmith, Journalist' went in search of Psmith novels other than 'Leave it to Psmith'.  And lo and behold there is 'Mike and Psmith' (a school story intended for a younger audience, but hey ho..), and a newly gifted copy od such has this on the second title page:

"This book is a product of its time and does not reflect the same values as it would if it were written today.  Parents might wish to discuss with their children how views on race have changed before allowing them to read this classic work".

Consequently, I read on thinking that there might be an African pupil with cannibal tendencies, an Indian with comically bad English or slighting references to a Jewish pupil.  This, however, was the sole reference to ethnicity:

"The Irish blood in him, which for the ordinary events of life made him merely energetic and dashing, now rendered him reckless".

Granted it is not the most PC of all possible descriptors, and it is a US published edition but I would not think it merited quite such a warning at the front.  Or am I being woefully insensitive?