[Glice]

I think it's more of a case of the word having two spellings - blonde being, I presume, from the French for white, hence the feminine ending. English English doesn't necessarily have masuline/ feminine forms, so it's less important to have the 'e' on the end. I think maybe last century blonde was the only 'correct' spelling, but over time letters come and go from spellings.

A bit like how the possessive suffix in English used to be -es (as in 'this is Dieseles horse'), whereas now we use the apostrophe to indicate possession (Diesel's horse). This, I think, came about as a result of something like Glice-es horse being a little cumbersome, while Glice's horse is quite easy. Also, there's the thing of how something like café and cafe both being acceptable in English English. I can't really comment on American English, however.