[INDY-1945] erase LAST_SENT_PP_SEQ_NO before starting view_change
[INDY-1945] erase LAST_SENT_PP_SEQ_NO before starting view_change

Signed-off-by: Andrew Nikitin <3988702a677b83abef1980fca266e406bb150845@dsr-corporation.com>

evernym/zeno,evernym/plenum