Bump chronos and presto. (#3159)

* Add some indicators to help fixing issue.

* Bump presto to help debugging.

* Fix compilation problems in presto.

* Fix SIGSEGV.

* Bump latest changes in chronos and presto.
Fix rare cases in validator_client.

* Use proper commits for chronos and presto.

beacon_chain/validator_client/duties_service.nim

@@ -126,8 +126,18 @@ proc pollForAttesterDuties*(vc: ValidatorClientRef,
     relevantDuties = duties.filterIt(
       checkDuty(it) and (it.pubkey in vc.attachedValidators)
     )
-    dependentRoot = currentRoot.get()
-    fork = vc.fork.get()
+    dependentRoot =
+      if currentRoot.isNone():
+        error "Unable to get current dependent root", epoch = epoch
+        return 0
+      else:
+        currentRoot.get()
+    fork =
+      if vc.fork.isNone():
+        error "Unable to get fork information", epoch = epoch
+        return 0
+      else:
+        vc.fork.get()
     genesisRoot = vc.beaconGenesis.genesis_validators_root
 
   let addOrReplaceItems =

vendor/nim-chronos

@@ -1 +1 @@
-Subproject commit 0c7a0bd0a5f9106612b841c5d9c20cd6776b4dde
+Subproject commit 7bf7e5548f31728cbcc5621171bd1e3b80207dd5

vendor/nim-presto

@@ -1 +1 @@
-Subproject commit bfcbeceb65d90b47af9adc94dcb671d7dd827443
+Subproject commit 1aedd3563232edf18a8d25ae7cedf2d066696572