installation: location of demo_table_jui.css

* Fixes location of demo_table_jui.css by explicitly referencing last
  git tag that contained the file.

Signed-off-by: Samuele Kaplun <samuele.kaplun@cern.ch>
Merge pull request #1954 from kaplun/fix-install-demo_table_jui

installation: location of demo_table_jui.css
WebStyle: POST handling fix

* Correctly handles reading using chunks in POST
  requests.

Co-authored-by: Alessio Deiana <alessio.deiana@cern.ch>
Signed-off-by: Samuele Kaplun <samuele.kaplun@cern.ch>