don't need groupConcat func written for android

it has 2 bugs (1) needs to be extended to return strings longer than 1K
(2) the following bug
      create table a1 (i int, j varchar(5));
    insert 2 rows with j = ''
      insert into a1 values(1,'');
      insert into a1 values(1,'');
    insert 2 rows with j = null
      insert into a1 (i) values (2);
      insert into a1 (i) values (2);
    with original sqlite3 groupConcat func
       select length(group_concat(j,' ')) from a1 where i = 1;
    result is
       1
    with android sqlite3 groupConcat func
       select length(group_concat(j,' ')) from a1 where i = 2;
    result is
       0