ch-03: don't use probe for route attempts

Usually probing is a sort of pre-processing step to see if the payment
is even possible.

03_how_ln_works.asciidoc

@@ -519,7 +519,7 @@ One common criticism of path-finding in the Lightning network is that it is unso
 
 Pathfinding and routing can be implemented in a number of different ways and multiple path-finding and routing algorithms can co-exist on the Lightning Network, just as multiple path-finding and routing algorithms exist on the internet. Source-based pathfinding is one of many possible solutions and is successful at the current scale of the Lightning Network.
 
-The pathfinding strategy currently implemented by Lightning nodes is to "probe" paths until one is found that has enough liquidity to forward the payment. This is an iterative process of trial and error, until success is achieved or no path is found. The algorithm currently does not necessarily result in the path with the lowest fees. While this is not optimal and certainly can be improved, even this simplistic strategy works quite well.
+The pathfinding strategy currently implemented by Lightning nodes is to iteratively try paths until one is found that has enough liquidity to forward the payment. This is an iterative process of trial and error, until success is achieved or no path is found. The algorithm currently does not necessarily result in the path with the lowest fees. While this is not optimal and certainly can be improved, even this simplistic strategy works quite well.
 
 This "probing" is done by the Lightning node or wallet and is not directly seen by the user.
 The user might only realize that probing is taking place if the payment does not complete instantly.