renepay: patch to assertion htlc_total<=known_max

In theory we should not have htlc_total<=known_max.
But for some strange race condition we do sometimes.
Until we find a solution to ensure the correct state
of the uncertainty network we remove the assertion.
Thanks to signed arithmetic and MIN guards, the rest
of the code in linearize_channel can handle the
weird cases with known_max<htlc_total.

Signed-off-by: Lagrang3 <lagrang3@protonmail.com>

plugins/renepay/mcf.c

@@ -470,8 +470,14 @@ static bool linearize_channel(const struct pay_parameters *params,
 		return false;
 	}
 
-	assert(
-	    amount_msat_less_eq(extra_half->htlc_total, extra_half->known_max));
+	/* FIXME: this assertion has been reported to be triggered in issue
+	 * #7535. A quick and dirty solution is to comment it and work-around
+	 * this case. But in principle if we do things the right way we should
+	 * not have htlc_total>known_max. The problem is likely to be
+	 * asynchronous way in which reserved htlcs are removed and known_max is
+	 * updated. */
+	// assert(
+	//    amount_msat_less_eq(extra_half->htlc_total, extra_half->known_max));
 	assert(
 	    amount_msat_less_eq(extra_half->known_min, extra_half->known_max));