http: add minimal HEAD support in the mover

some clients do send HEAD after redirect

Acked-by: Gerd Behrmann
Target: master
Require-book: no
Require-notes: no
(cherry picked from commit 8040e1ec8c639824ec283b4d2a4dc4b135cc6186)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
http: fix multipart response size

Acked-by: Paul Millar
Target: master
Require-book: no
Require-notes: no
(cherry picked from commit 5c63d0e26a408eacd1c5d8d8398e47fd3eaad045)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge pull request #639 from kofemann/fix-davix-2.6

Fix davix 2.6