Update installation.asciidoc

[orberkov]

typo

[cla-checker-service]

❌ Author of the following commits did not sign a Contributor Agreement:
e86f6dd

Please, read and sign the above mentioned agreement if you want to contribute to this project

[swallez]

Good catch @orberkov, thanks. Unfortunately this documentation has been updated in #265.

In order to move this PR forward, please:

• sign the CLA (contributor license agreement) as explained above,
• rebase your PR so that it targets the main branch (I will take care of backporting to other branches)
• update the PR to resolve the conflict with the updated documentation.

Alternatively, you can also close this PR and open a new one (for the main branch), or let us fix the typo now that we're aware of it.