Fix loki and http output 1.19.3

[nniehoff]

This PR should NOT be merged.

The goal of this PR is to build on #1 and add the temporary fix to allow Telegraf loki plugin to succeed on 400 responses. Loki currently drops logs if they are out of order, however they are working on addressing this in grafana/loki#1544.

The goal of this PR is to track the changes/fixes made in the branch fix-http-output-1.19.2 to the http output plugin.

This PR shouldn't be merged.

This change was made as a temporary fix to allow Telegraf to remote-write data into Thanos using the HTTP output plugin.

By design Thanos will return a 409 when some data can't be ingested for various reasons and the client should drop these metrics. Without this fix, Telegraf will try to resend all data after receiving a 409 response code, which blocks all data to be send to Thanos until the faulty block expires.

[nniehoff]

For reference to build the packages I used the following command:

make amd64=1 i386=1 package