Explicitly set chain limits in replace-by-fee test

qa/rpc-tests/replace-by-fee.py

@@ -73,7 +73,12 @@ class ReplaceByFeeTest(BitcoinTestFramework):
     def setup_network(self):
         self.nodes = []
         self.nodes.append(start_node(0, self.options.tmpdir, ["-maxorphantx=1000",
-                                                              "-relaypriority=0", "-whitelist=127.0.0.1"]))
+                                                              "-relaypriority=0", "-whitelist=127.0.0.1",
+                                                              "-limitancestorcount=50",
+                                                              "-limitancestorsize=101",
+                                                              "-limitdescendantcount=200",
+                                                              "-limitdescendantsize=101"
+                                                              ]))
         self.is_network_split = False
 
     def run_test(self):