refactor(client): Small cosmetic cleanup in ua_client_internal.h
refactor(client): Small cosmetic cleanup in ua_client_internal.h

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