MQTT: Implements reconnecting in publish thread in case thread is waken-up but client is disconnected.
Note: paho's lostConnection callback got already disabled in previous commit.
<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>