I think this may be related:
$ readelf --dynamic libmysqlclient.so.21.1.19 | grep BIND 0x000000000000001e (FLAGS) BIND_NOW
$ readelf --dynamic libmysqlclient.so.21.1.21 | grep BIND 0x000000000000001e (FLAGS) BIND_NOW STATIC_TLS
I think this may be related:
$ readelf --dynamic libmysqlclient. so.21.1. 19 | grep BIND
0x000000000000001e (FLAGS) BIND_NOW
$ readelf --dynamic libmysqlclient. so.21.1. 21 | grep BIND
0x000000000000001e (FLAGS) BIND_NOW STATIC_TLS