CORDA-1628 - Increase max restart count for notary client flows. (#3357) (#3603)

This will ensure that the notary client flow will retry over a sufficient
period of time for the notary to update its network map.

With a backoff base of 1.8 and 5 retries the last retry will fire after
about 20 min 8 sec of the initial flow start:

0	30
1	54
2	97.2
3	174.96
4	314.928
5	566.8704

Total 1207.9584	= 20.13264 min

node/src/main/resources/reference.conf

@@ -27,4 +27,9 @@ activeMQServer = {
 rpcSettings = {
     useSsl = false
     standAloneBroker = false
-}
+}
+flowTimeout {
+    timeout = 30 seconds
+    maxRestartCount = 5
+    backoffBase = 1.8
+}