[1741] rename RESOLVER_SHUTDOWN debug message

it conflicted with RESOLVER_SHUTDOWN info message (the debug one signals the shutdown command was received, the info message that the resolver actually shut down)

src/bin/resolver/main.cc

@@ -100,7 +100,8 @@ my_command_handler(const string& command, ConstElementPtr args) {
                     return (answer);
                 }
             }
-            LOG_DEBUG(resolver_logger, RESOLVER_DBG_INIT, RESOLVER_SHUTDOWN);
+            LOG_DEBUG(resolver_logger, RESOLVER_DBG_INIT,
+                      RESOLVER_SHUTDOWN_RECEIVED);
             io_service.stop();
         }
 

src/bin/resolver/resolver_messages.mes

@@ -247,6 +247,6 @@ The log message shows the query in the form of <query name>/<query
 type>/<query class>, and the client that sends the query in the form of
 <Source IP address>#<source port>.
 
-% RESOLVER_SHUTDOWN asked to shut down, doing so
+% RESOLVER_SHUTDOWN_RECEIVED received command to shut down
 A debug message noting that the server was asked to terminate and is
 complying to the request.