changed pkg order to install "bareos-database-mysql" or "bareos-database-postgresql" or others.
Before always the "bareos-database-postgresql" was installed. and the mysql always after that. 

that comes from the dependencies in the bareos-database-common

apt-cache depends bareos-database-common
bareos-database-common
  | PreDepends: debconf
   PreDepends: <debconf-2.0>
     cdebconf
     debconf
   Depends: bareos-common
  | Depends: bareos-database-postgresql
  | Depends: bareos-database-mysql
   Depends: bareos-database-sqlite3
   Depends: dbconfig-common
   Depends: lsb-base
   Depends: libc6
   Depends: libgcc1
   Depends: libstdc ++ 6