Modify rule IDs for whitelisting rules

[studersi]

Unclear Step 8: Writing simple whitelist rules

Not clear that the rules introduced in this step replace the rule added in
step 7. The only indication is that the rule ID 10000 appears twice.

162 of /opt/apache-2.4.29/conf/httpd.conf: ModSecurity: Found another rule
with the same id ```

Yes, I'm aware of that. I have a note here telling me to move the whitelisting
rules +1000 to make sure there are no longer any collisions.

[dune73]

Change performed in commit

e13a443

Could you please check this works as intended?

[studersi]

Your commit creates a new collision later in the tutorial. It is addressed in PR #83.