package/paho-mqtt-c: bump to version 1.3.8
https://github.com/eclipse/paho.mqtt.c/milestone/15?closed=1
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit f811ecd79be150c5c7aba0d83b08629d88df3aba)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>