SoupServer: fix to not allow smuggling ".." into path
SoupServer: fix to not allow smuggling ".." into path

When SoupServer:raw-paths was set (the default), it was possible to
sneak ".." segments into the path passed to the SoupServerHandler,
which could then end up tricking some handlers into retrieving
arbitrary files from the filesystem. Fix that.

https://bugzilla.gnome.org/show_bug.cgi?id=653258

jwendell/libsoup,fanc999/libsoup,fanc999/libsoup,Distrotech/libsoup,Distrotech/libsoup,jwendell/libsoup,ahmedammar/platform_external_gst_libsoup,ahmedammar/platform_external_gst_libsoup,fanc999/libsoup,jwendell/libsoup,fanc999/libsoup,Distrotech/libsoup,fanc999/libsoup,Distrotech/libsoup,ahmedammar/platform_external_gst_libsoup,jwendell/libsoup,jwendell/libsoup,Distrotech/libsoup