Update anyarray_remove.sql

Fix a bug where if the second (right hand side) array contains NULL, then the function will result in an empty array. E.g.,

    SELECT '{"one","two","three"}'::text[] - '{"two",NULL}'::text[]
    -- Returns: {}
Merge pull request #5 from cpburnz/patch-1

Update anyarray_remove.sql, fixed bug in anyarray_remove when second arg is NULL