[MSSQL] Use schema for key lookup

Author: NathanW2

src/providers/mssql/qgsmssqlprovider.cpp

@@ -418,7 +418,7 @@ void QgsMssqlProvider::loadFields()
     {
       query.clear();
       query.setForwardOnly( true );
-      if ( !query.exec( QString( "exec sp_pkeys N'%1', NULL, NULL" ).arg( mTableName ) ) )
+      if ( !query.exec( QString( "exec sp_pkeys @table_name = N'%1', @table_owner = '%2' " ).arg( mTableName, mSchemaName ) ) )
       {
         QString msg = query.lastError().text();
         QgsDebugMsg( msg );