ghttp: Fix warning.

This fixes:
> module-ghttp.c: In function 'module_ghttp':
> module-ghttp.c:553:14: warning: assignment from incompatible pointer type [enabled by default]
>   ph->c_capmt = ghttp_capmt_notify;
>               ^

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@8728 4b0bc96b-bc66-0410-9d44-ebda105a78c1