_removeErrorNotification() function is also called manually without an event

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>
Fix typo

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>
.addBack( selector ) replaces .andSelf()

Signed-off-by: Madhura Jayaratne <madhura.cj@gmail.com>