lnrouter: LiquidityHint: fix logic bug in calculation

Reported privately by Zuzana Kotásková <[email protected]>

Author: SomberNight

electrum/lnrouter.py

@@ -281,7 +281,7 @@ def remove_htlc(self, is_forward_direction: bool):
         if is_forward_direction:
             self._inflight_htlcs_forward = max(0, self._inflight_htlcs_forward - 1)
         else:
-            self._inflight_htlcs_backward = max(0, self._inflight_htlcs_forward - 1)
+            self._inflight_htlcs_backward = max(0, self._inflight_htlcs_backward - 1)
 
     def __repr__(self):
         return f"forward: can send: {self._can_send_forward} msat, cannot send: {self._cannot_send_forward} msat, htlcs: {self._inflight_htlcs_forward}\n" \