HTTPD instrumentation: Safe modification of httpd.conf

[CostisC]

Description:
The Include /usr/local/apache2/conf/opentemetry_agent.conf may be appended on the same line with the last httpd.conf statement, if there is not a blank last line in httpd.conf. This results in a corrupted httpd configuration, and the service will not start.

It is safer that an empty line comes before the addition of Include ...opentemetry_agent.conf, as a protection measure against such cases.

Link to tracking Issue(s): N/A

Testing: Change httpd.conf to not have an blank last line, and then restart the instrumented httpd pod. It fails to start up.

Documentation: N/A

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: CostisC / name: Costis C. (adcae80, 401a137, 1b6b970, 07ac8b8, eb8c97e)

[swiatekm]

Thank you for the contribution! Could you add a changelog entry to this PR? Running make chlog-new in the operator root directory will create a template file in .chloggen that you can fill in.