HTTP interface status.xml : round equalizer.bands

Tested with the latest version of VLC (2.0.1-1) under Archlinux, tested also by upgrading httprequests.lua to the git HEAD.

Got the following error :

Error loading /requests/status.xml/usr/lib/vlc/lua/intf/modules/httprequests.lua:34: attempt to perform arithmetic on local 'what' (a string value)

To reproduce it, just enable "Graphic Equalizer".

To fix it I applied the attached patch :

• Fix the root problem (remove the round of s.equalizer.bands)
• Make the round function safer