Fix node cache lifetime parameter not applying

main.go

@@ -50,7 +50,7 @@ type configParams struct {
 	AllowUnbalanceTo    bool     `long:"allow-unbalance-to" description:"let the target channel go above 50% local liquidity, use if you want to refill a channel; you should also set --pto to >50" json:"allow_unbalance_to" toml:"allow_unbalance_to"`
 	StatFilename        string   `short:"s" long:"stat" description:"save successful rebalance information to the specified CSV file" json:"stat" toml:"stat"`
 	NodeCacheFilename   string   `long:"node-cache-filename" description:"save and load other nodes information to this file, improves cold start performance"  json:"node_cache_filename" toml:"node_cache_filename"`
-	NodeCacheLifetime   int      `long:"node-cache-lifetime" description:"nodes with last update older than this time (in minutes) will be removed from cache after loading it" json:"node_cache_lifetime" toml:"node_cache_lifetime" default:"1440"`
+	NodeCacheLifetime   int      `long:"node-cache-lifetime" description:"nodes with last update older than this time (in minutes) will be removed from cache after loading it" json:"node_cache_lifetime" toml:"node_cache_lifetime"`
 	NodeCacheInfo       bool     `long:"node-cache-info" description:"show red and cyan 'x' characters in routes to indicate node cache misses and hits respectively" json:"node_cache_info" toml:"node_cache_info"`
 }
 
@@ -368,6 +368,9 @@ func preflightChecks(params *configParams) error {
 		return fmt.Errorf("use either relative amounts or rapid rebalance but not both")
 
 	}
+	if params.NodeCacheLifetime == 0 {
+		params.NodeCacheLifetime = 1440
+	}
 
 	return nil