Akonadi pg backend runs erroneous "alter table" queries at startup. I tries to convert a colum to text, but it is already of type text. The pg function convert_from() requires a bytea as first argument.

Maybe it worked with older versions of postgres, which had an implicit text to bytea cast.

Incidentally, it is strange that akonadi would need to run any "alter table" query on a freshly-created database.

Reproducible: Always

Steps to Reproduce:
1. start postgres 9.2 server
2. createdb akonadi
3. configure pg backend using akondiconsole
4. restart akonadi server
5. click "test..." in akonadiconsole 
Actual Results:  
Current Akonadi server error log found:


DBUpdater: query error: "ERROR:  function convert_from(text, unknown) does not exist
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
(42883) QPSQL: Unable to create query" " " 
Query was:  "ALTER TABLE CollectionTable ALTER remoteId TYPE text USING convert_from(remoteId,'utf8');" 
Target version was:  24 
Mandatory:  false 
DBUpdater: query error: "ERROR:  current transaction is aborted, commands ignored until end of transaction block
....
Failed to commit transaction for database update.

Expected Results:  
No error.

Using PG 9.2, akonadi 1.10.3, qtsql 4.8.5