device: remove pending dhcp actions also in IP_DONE state

When the IP status is IP_DONE and a DHCP transaction succeeds the
'dhcp4' and 'dhcp6' pending actions must be removed. Without this, a
temporary link loss just after the activation would cause a DHCP
restart and those actions would remain set, blocking the startup.

https://bugzilla.redhat.com/show_bug.cgi?id=1330893

src/devices/nm-device.c

@@ -4545,6 +4545,8 @@ dhcp4_lease_change (NMDevice *self, NMIP4Config *config)
 	                    NULL,
 	                    NULL);
 
+	nm_device_remove_pending_action (self, PENDING_ACTION_DHCP4, FALSE);
+
 	return TRUE;
 }
 
@@ -5297,6 +5299,8 @@ dhcp6_lease_change (NMDevice *self)
 	                    nm_device_get_applied_connection (self),
 	                    self, NULL, NULL, NULL);
 
+	nm_device_remove_pending_action (self, PENDING_ACTION_DHCP6, FALSE);
+
 	return TRUE;
 }