only set UA_CONNECTION_OPENING when we have a valid socket
only set UA_CONNECTION_OPENING when we have a valid socket

StalderT/open62541,StalderT/open62541,JGrothoff/open62541,open62541/open62541,StalderT/open62541,JGrothoff/open62541,jpfr/open62541,JGrothoff/open62541,JGrothoff/open62541,open62541/open62541,open62541/open62541,jpfr/open62541,StalderT/open62541,open62541/open62541,jpfr/open62541,jpfr/open62541