Ensure nMaxOutboundTotalBytesSentInCycle and nMaxOutboundCycleStartTime are initialized even if CConnman::Start() is not called. Prevents failures in test/fuzz/connman when run under valgrind.
nTotalBytesRecv and nTotalBytesSent are already initialized in the class definition, and CConnman::Start is only called once in AppInitMain, so removing the reinitialization in Start has no impact.
This is a backport of core#20408