Fix obsolete comment regarding NOTICE message level.

By default NOTICE message is not sent to server log because
the default value of log_min_messages is WARNING since 8.4.

Pavel Stehule

src/include/utils/elog.h

@@ -33,8 +33,8 @@
 								 * client regardless of client_min_messages,
 								 * but by default not sent to server log. */
 #define NOTICE		18			/* Helpful messages to users about query
-								 * operation; sent to client and server log by
-								 * default. */
+								 * operation; sent to client and not to server
+								 * log by default. */
 #define WARNING		19			/* Warnings.  NOTICE is for expected messages
 								 * like implicit sequence creation by SERIAL.
 								 * WARNING is for unexpected messages. */