RemoveText() fails to remove text in some cases
before mPreviousNumberOfCharacters of mTextUpdateInfo is updated.
In all text remove situation, it can be removed regardless of the update of this info.
It's same as the previous preedit all remove behavior.
Change-Id: I909b8bcf5edd8466595d93a0d8e5d3ee960a8f50
Signed-off-by: Bowon Ryu <bowon.ryu@samsung.com>