[debian-mysql] Bug#918988: Bug#918988: libmariadbclient18: conflict with libmysqlclient18

[Otto Kekäläinen]

Potentially related:
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916375 apache2:
Segmentation fault when mod_perl.so is enabled
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=918988
libmysqlclient symbol conflict segfaulted Apache
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=920619
libaprutil1-dbd-mysql should also be added to the Breaks-list