Fix httpd config option 'keep_alive_timeout'

The documentation states that the value is in seconds, which was true
when using the Apache like configuration file, but not true when using
the proplist style configuration.
Fix httpd config option 'script_timeout'

This fixes the usage of the httpd configuration option 'script_timeout',
which got ignored before.

The documentation states that the value is in seconds, which was true
when using the Apache like configuration file, but not true when using
the proplist style configuration.
Add test for httpd config option 'script_timeout'

The option got ignored before 720721e.
inets: added testcase for keep_alive_timeout
fix a little typo in public_key documentation

In the example of `public_key:pem_entry_encode/2`, the result
should match to `PemEntry` rather than to `PemBin` since `PemEntry`
is expected as an input argument of `public_key:pem_encode/1` called
just on the next line of the example.
Merge branch 'ztmr/fix_public_key_doc/OTP-11380' into maint

* ztmr/fix_public_key_doc/OTP-11380:
  fix a little typo in public_key documentation
Merge branch 'weisslj/fix-httpd-timeout-options/OTP-11276' into maint

* weisslj/fix-httpd-timeout-options/OTP-11276:
  inets: added testcase for keep_alive_timeout
  Add test for httpd config option 'script_timeout'
  Fix httpd config option 'script_timeout'
  Fix httpd config option 'keep_alive_timeout'