Distributions miss license header from WebPDecoder.js

[stefan6419846]

It seems like the license data from https://github.com/parallax/jsPDF/blob/master/src/libs/WebPDecoder.js is missing inside the distributed files, for example at https://github.com/parallax/jsPDF/blob/bfeae27a27087f9a3279031959086cb7ff7bcaee/dist/jspdf.umd.js#L25237-L25243