improve an error uncovered by clang
improve an error uncovered by clang

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