Add time to "starting keepalive" message

Matches the pvchealthd output and provides a useful message detail to
this otherwise contextless message.

node-daemon/pvcnoded/util/keepalive.py

@@ -701,7 +701,7 @@ def node_keepalive(logger, config, zkhandler, this_node):
 
         runtime_start = datetime.now()
         logger.out(
-            "Starting node keepalive run",
+            "Starting node keepalive run at {datetime.now()}",
             state="t",
         )