don't crash on trying to change IP interface for Beremiz_service using taskbar icon if IP wasn't previously
By default IP is not set (None) and service listen only on localhost interface.
<xsd:element name="Xenomai">
<xsd:complexType>
%(toolchain_gcc)s
<xsd:attribute name="XenoConfig" type="xsd:string" use="optional" default="xeno-config"/>
</xsd:complexType>
</xsd:element>