State is overwritten in the constructor

[dallanmc]

I believe the call to initialize state by setting state to initialState in the constructor subsequently gets overwritten in the next line this.state = {...}.

book-rest-api-reactjs/src/main/webapp/reactjs/src/components/Book/Book.js

Line 16 in a19c89b

this.state = {

Also, thanks for the excellent tutorial on youtube!