And so you can solve the problem.
Give in the Shell following line:
apt-cache show mysql-common | grep Version
The following output should appear
Version: 5.6.19-1~dotdeb.1
Version: 5.5.39+maria-1~wheezy
Version: 5.5.38-0+wheezy1
Version: 5.5.37-0+wheezy1
Next, you give the shell the following line:
apt-cache show libmysqlclient18 | grep Version
Again, you should get identical output
Version: 5.6.19-1~dotdeb.1
Version: 5.5.39+maria-1~wheezy
Version: 5.5.38-0+wheezy1
Version: 5.5.37-0+wheezy1
The points marked green should be consistent with that in the introduction. If so give a your following command in the Shell:
apt-get install mariadb-server-5.5 mariadb-client-5.5 libmysqlclient18=5.5.39+maria-1~wheezy mysql-common=5.5.39+maria-1~wheezy
Now the question should come if you want to install the packages.