[cifX firmware] taglist value for number of joinable IGMP Multicasts is not handled as expected

The number of joinable IGMP groups for Socket API is set via taglist. Currently, cifX firmware (and only for cifX firmware) allows joining more groups than specified if a SystemReset is performed. Without SystemReset all works as expected.

For all Profinet firmware, which does not use IGMP itself, It is expected that max one more group can be joined compared to the taglist setting.