add backtick to fix mysql  database name contain special  characters (#5054)
add backtick to fix mysql  database name contain special  characters (#5054)

when use mysql storage, set` database = "dev-dassets-bc"` , create database and create table will throw exceptions as follows:

    Error initializing storage of type mysql: failed to create mysql database: Error 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-dassets-bc' at line 1
    Error initializing storage of type mysql: failed to create mysql table: Error 1046: No database selected

cause of `-` is  a MySQL  built-in symbol. so add backtick for create database sql\create table sql \dml sqls.
hashicorp/vault,quixoten/vault,hartsock/vault,rnaveiras/vault,hashicorp/vault,joelthompson/vault,joelthompson/vault,quixoten/vault,hartsock/vault,joelthompson/vault,rnaveiras/vault,hartsock/vault,rnaveiras/vault,hashicorp/vault,quixoten/vault,hartsock/vault,kingland/vault,kingland/vault,joelthompson/vault,hartsock/vault,kingland/vault,hashicorp/vault,rnaveiras/vault,kingland/vault,rnaveiras/vault,hashicorp/vault,quixoten/vault,kingland/vault,hashicorp/vault