Switch default xlog level from ERR to NOTICE

ERR is too scary for a default value :)

(cherry picked from commit c290071)

xlog.c

@@ -49,7 +49,7 @@ int xlog_buf_size = 4096;
 int xlog_force_color = 0;
 
 /* the log level used when printing xlog messages */
-int xlog_print_level = L_ERR;
+int xlog_print_level = L_NOTICE;
 
 /* the logging level/threshold for filtering the xlog messages for printing */
 static int xlog_level_default = L_NOTICE;