Correct Concurrency section code example

Docs/PipelinesMultiplexers.md

@@ -97,7 +97,7 @@ Concurrency
 It should be noted that the pipeline / multiplexer / future-value approach also plays very nicely with continuation-based asynchronous code; for example you could write:
 
 ```C#
-string value = await db.StringGet(key);
+string value = await db.StringGetAsync(key);
 if (value == null) {
     value = await ComputeValueFromDatabase(...);
     db.StringSet(key, value, flags: CommandFlags.FireAndForget);