Fixes ibus_engine_update_lookup_table_fast method

gnome shell needs the previous page and next page
to correctly show the page up/down arrows,
send three pages instead of one page.

URL: https://bugzilla.gnome.org/show_bug.cgi?id=703020

BUG=

Review URL: https://codereview.appspot.com/164540045
Patch from Peng Wu <alexepico@gmail.com>.