Correcting the output message

It used to take the database name for the connection name which can be very confusing
When I have only one connection in my project not `named`( as far as I understand what naming a connection means ).

```yaml
doctrine:
    dbal:
        driver:   "%database_driver%"
        host:     "%database_host%"
        port:     "%database_port%"
        dbname:   "symfony_test"
        user:     "%database_user%"
        password: "%database_password%"
        charset:  UTF8
```
If I run the command 
```
php app/console doc:database:create
```
The result is 
```
Created database for connection named `symfony_test`
```

Which is a bit weird but maybe when no name is given to a connection the database name is use as default value.

Now if I have multiple connection named differently
```yaml
doctrine:
    dbal:
        default_connection: default
        connections:
            default:
                driver:   "%database_driver%"
                host:     "%database_host%"
                port:     "%database_port%"
                dbname:   "symfony_test"
                user:     "%database_user%"
                password: "%database_password%"
                charset:  UTF8
            migration:
                driver:   "mysqli"
                host:     "%database_host%"
                port:     "%database_port%"
                dbname:   "symfony_test2"
                user:     "%database_user%"
                password: "%database_password%"
                charset:  UTF8
```
If I want to create the database from the migration connection I need to do:
```
php app/console doc:database:create --connection="migration"
```
And I get : 
```
Created database for connection named `symfony_test2`
```

Which seems really strange to me ?