e_client: check ec->new_client in e_client_desk_set

e_client: check ec->new_client in e_client_desk_set

There was a bug that the external contents (such as splash) didn't set
because evas_object_show was called in e_client_desk_set.

When evas_object_show is called, then e makes the cw->obj using
E_COMP_OBJECT_CONTENT_TYPE_INT_IMAGE in _e_comp_intercept_show function.
So, after calling evas_object_show, e_comp_object_content_set always returns EINA_FALSE
because ec->obj is alread existed.

To resolve this problem, we add code checking ec->new_client.
If ec->new_client is set, then we don't force call evas_object_show in e_client_desk_set.

Change-Id: Ib0514726ba60aa3edd66d932b40463a5d3b91043