fix db installer host name

[maximemulder]

Brief summary of changes

Fix the database installer so that the 'Host' field name matches the name found in the database. This difference prevented Loris from being installed on systems in which the database returns tables whose field names are capitalized according to their name in the database, and not in the query (our dev VMs does the latter, hence why we did not have this bug during development).

Testing instructions

Run the database installer on a system with a database whose returned field names are not capitalized according to the query.

Links to related issues

• Seems to solve Incorrect field capitalization in queries lead to bugs with MariaDB #9101. However, there might be more places where the query capizalization does not match that of the database, so I would advise against closing this issue until some way to check this more exhaustively has been found.

[driusan]

@nicolasbrossard can you review and test?

[ridz1208]

@maximemulder changes look good, pending check on other locations to approve

[maximemulder]

@maximemulder changes look good, pending check on other locations to approve

Done (I probably should have done that before tbh, my fault). I also looked for other uses of mysql.user elsewhere in the code, but I did not find any (search mysql.user / `mysql`.`user`).

Also, as explained in the following comment, this change must be tested on MariaDB >= 10.4
#9101 (comment)
Considering the root cause has been found, I think the issue can be closed once this PR is mergred.