msm: ipa: Fix to reset the sticky_rear flag

When hotspot tethering is toggled quickly
WLAN_AP_CONNECT is received even before all
the filter rules are cleaned up for the previous
DISCONNECT. As the sticky_rear is set, default
rule is not added at the end. Make a change to
reset sticky_rear when default rules are deleted.

Change-Id: I8b63fec360e91ddd5f5267fe74c769547bb5bbfe
Acked-by: Chaitanya Pratapa <cpratapa@qti.qualcomm.com>
Signed-off-by: Utkarsh Saxena <usaxena@codeaurora.org>