f! test: fix tests after ln_init changes

Author: pinheadmz

test/data/network_with_plugins/network.yaml

@@ -27,7 +27,7 @@ nodes:
         bitcoin.timelockdelta=33
       channels:
         - id:
-            block: 300
+            block: 500
             index: 1
           target: tank-0004-ln
           capacity: 100000
@@ -44,7 +44,7 @@ nodes:
     lnd:
       channels:
         - id:
-            block: 300
+            block: 500
             index: 2
           target: tank-0005-ln
           capacity: 50000