e_client: send E_EVENT_CLIENT_REMOVE event when an ec is deleted

e_client: send E_EVENT_CLIENT_REMOVE event when an ec is deleted

There was a bug that the E_Process kept the deleted ec pointer (dangling) in the ec_lists.

When the ec which sent E_EVENT_CLIENT_ADD event and set new_client flag to 1 was deleted,
E could not send E_EVENT_CLIENT_REMOVE event because its new_client flag was 1.
By this, e_process didn't get the E_EVENT_CLIENT_REMOVE and didn't remove ec from ec_lists.

This patch resolve this problem.
We change code to send E_EVENT_CLIENT_REMOVE always if E_EVENT_CLIENT_ADD was sent before.

Change-Id: Iac5f683a9fb2aacd897ec07f4b0ab46c5e396d8d