bugfix: consider own policy for last hop

the idea is to ignore channels as the last hop if we'd earn less by sending the
rebalanced sats back through that channel, compared to what we won't be able to
earn because we take funds out of the channel of the first hop

logic.py

@@ -53,20 +53,17 @@ def rebalance(self):
             )
 
         payment_request = self.generate_invoice()
-        min_fee_last_hop = None
+        min_ppm_last_hop = None
         if self.econ_fee and self.first_hop_channel:
             policy_first_hop = self.lnd.get_policy_to(self.first_hop_channel.chan_id)
-            fee_rate = policy_first_hop.fee_rate_milli_msat
-            min_fee_last_hop = self.econ_fee_factor * self.compute_fee(
-                self.amount, fee_rate, policy_first_hop
-            )
+            min_ppm_last_hop = self.econ_fee_factor * policy_first_hop.fee_rate_milli_msat
         routes = Routes(
             self.lnd,
             payment_request,
             self.first_hop_channel,
             self.last_hop_channel,
             fee_limit_msat,
-            min_fee_last_hop,
+            min_ppm_last_hop,
         )
 
         self.initialize_ignored_channels(routes, fee_limit_msat)

routes.py

@@ -13,7 +13,7 @@ def __init__(
         first_hop_channel,
         last_hop_channel,
         fee_limit_msat,
-        min_fee_msat_last_hop,
+            min_ppm_last_hop,
     ):
         self.lnd = lnd
         self.payment_request = payment_request
@@ -25,7 +25,7 @@ def __init__(
         self.ignored_nodes = []
         self.num_requested_routes = 0
         self.fee_limit_msat = fee_limit_msat
-        self.min_fee_msat_last_hop = min_fee_msat_last_hop
+        self.min_ppm_last_hop = min_ppm_last_hop
 
     def has_next(self):
         self.update_routes()
@@ -112,9 +112,11 @@ def ignore_hop_on_route(self, hop_to_ignore, route):
 
     def ignore_high_fee_hops(self, route):
         ignore = []
-        if self.min_fee_msat_last_hop:
+        if self.min_ppm_last_hop:
             last_hop = route.hops[-1]
-            if last_hop.fee_msat < self.min_fee_msat_last_hop:
+            policy = self.lnd.get_policy_to(last_hop.chan_id)
+            ppm_last_hop = policy.fee_rate_milli_msat
+            if ppm_last_hop < self.min_ppm_last_hop:
                 ignore.append(last_hop)
         max_fee_msat = 0
         max_fee_hop = None