Removing INFLUXDB_HTTP_LOG from logparser usage/docs

this log format is likely soon going to be removed from a future
influxdb release, so we should not be recommending that users base any
of their log parsing infra on this.

etc/telegraf.conf

@@ -1577,7 +1577,7 @@
 #   ##   /var/log/**.log     -> recursively find all .log files in /var/log
 #   ##   /var/log/*/*.log    -> find all .log files with a parent dir in /var/log
 #   ##   /var/log/apache.log -> only tail the apache log file
-#   files = ["/var/log/influxdb/influxdb.log"]
+#   files = ["/var/log/apache/access.log"]
 #   ## Read file from beginning.
 #   from_beginning = false
 #
@@ -1590,9 +1590,9 @@
 #     ## Other common built-in patterns are:
 #     ##   %{COMMON_LOG_FORMAT}   (plain apache & nginx access logs)
 #     ##   %{COMBINED_LOG_FORMAT} (access logs + referrer & agent)
-#     patterns = ["%{INFLUXDB_HTTPD_LOG}"]
+#     patterns = ["%{COMBINED_LOG_FORMAT}"]
 #     ## Name of the outputted measurement name.
-#     measurement = "influxdb_log"
+#     measurement = "apache_access_log"
 #     ## Full path(s) to custom pattern files.
 #     custom_pattern_files = []
 #     ## Custom patterns can also be defined here. Put one pattern per line.