Increase harvester get content chunk size

[seitenbau-govdata]

We have some RDF endpoints which delivers a big dump file with thousands of datasets resulting in a large file of up to 100 MB. And we have noticed that getting the whole content takes a very long time and sometime even gets interrupted. The reason is the small chunk size of 1 KB. So we like to increase the chunk size up to 512 KB.

[amercader]

That sounds very reasonable