Allow for leading zero in chunk lengths for chunked transfer encoding
Some web servers use "Transfer-Encoding: chunked" when transferring the body of an HTTP response.
According to the HTTP/1.1 Specification section 3.6.1 the chunk length is encoded as one or more hex digits followed by an optional chunk extension introduced by semicolon or CR+LF. There is no requirement for the first digit of the chunk extension to be non-zero.
Currently the AcornHTTP header interpretation assumes that if there is a leading zero then the number of bytes is zero. This causes some fetches to fail. The example I encountered was the WikiData API endpoint at https://query.wikidata.org/sparql
The fix appears to be a simple matter of removing the check for the leading zero, as the actual value of the hex number has already been calculated a few lines further up.
I don't know what incantations are needed to increase the module number. The merge request only includes the actual code change.