Missing comma in config example

Author: michaelklishin

docs/rabbitmq.config.example

@@ -248,7 +248,7 @@
 
    %% The total memory available can be calculated from the OS resources
    %% - default option - or provided as a configuration parameter:
-   %% {total_memory_available_override_value, "5000MB"}
+   %% {total_memory_available_override_value, "5000MB"},
 
    %% Set disk free limit (in bytes). Once free disk space reaches this
    %% lower bound, a disk alarm will be set - see the documentation