spelling: variable

(cherry picked from commit b57e847)

Author: jsoref

docs/rabbitmq-service.8

@@ -115,7 +115,7 @@ Defaults to
 for 64-bit environments).
 This is the installation location of the Erlang service manager.
 .It Ev RABBITMQ_CONSOLE_LOG
-Set this varable to
+Set this variable to
 .Sy new or
 .Sy reuse
 to have the console output from the server redirected to a file named