tdf#122437 mysqlc: fix foreign key name query

Correct query of the foreign key constraint name is required for
dropping foreign keys.

Change-Id: Id98b0672ec5a8a06039667a06cb0afd97b3ee205
Reviewed-on: https://gerrit.libreoffice.org/65861
Tested-by: Jenkins
Reviewed-by: Tamás Bunth <btomi96@gmail.com>

connectivity/source/drivers/mysqlc/mysqlc_databasemetadata.cxx

@@ -952,7 +952,7 @@ Reference<XResultSet> SAL_CALL ODatabaseMetaData::getImportedKeys(const Any& /*c
         // delete rule
         aRow.push_back(makeAny(xRow->getShort(8)));
         // foreign key name
-        aRow.push_back(makeAny(xRow->getShort(9)));
+        aRow.push_back(makeAny(xRow->getString(9)));
         // primary key name
         aRow.push_back(makeAny(OUString{})); // TODO
         // deferrability