test: get rid of redundant TODO tag

The 'FEE' parameter in test/functional/feature_dbcrash.py::
generate_small_transaction() is not a fee rate, but an
absolute fee. Hence, it doesn't make sense to replace it
with node relay based fee calculation. Get rid of the TODO
comment suggesting otherwise.

Author: Chandra Pratap

test/functional/feature_dbcrash.py

@@ -184,7 +184,7 @@ def verify_utxo_hash(self):
             assert_equal(nodei_utxo_hash, node3_utxo_hash)
 
     def generate_small_transactions(self, node, count, utxo_list):
-        FEE = 1000  # TODO: replace this with node relay fee based calculation
+        FEE = 1000
         num_transactions = 0
         random.shuffle(utxo_list)
         while len(utxo_list) >= 2 and num_transactions < count: