Sqlite: Remove unused code

Binding by names is slower and we never used it.

Change-Id: Ia6b9b78401f8c2711be34b667ac6f08b44418773
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/libs/sqlite/sqlitewritestatement.h

@@ -37,7 +37,6 @@ public:
     using StatementImplementation::execute;
     using StatementImplementation::database;
     using StatementImplementation::write;
-    using StatementImplementation::writeNamed;
 
 protected:
     void checkIsWritableStatement();