fix(tests): Fix a GCC11 warning in check_client.c
fix(tests): Fix a GCC11 warning in check_client.c

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