Bad namespace separator

Description of the issue0

After security update of libexpat the biboumi refuses to start with error:

Xml_Parsebuffer encountered an error: out of memory

According the debian bug [1] discusion, it is not libexpat problem, but biboumi uses bad namespace separator, which is highlighted by current security update patches and the error string out of memory is missleading, and means syntax error in real. See details at [2] & [3].

• [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1006333
• [2] https://alioth-lists.debian.net/pipermail/pkg-voip-maintainers/2022-February/036223.html
• [3] https://github.com/libexpat/libexpat/issues/572#issuecomment-1050119036