Fix escaping of pipe character in reference tables

[dreis2211]

Hi,

while working on #18371 I noticed that there are some issues with the handling of | inside tables in the reference docs. Here's a list of issues that I found, but there might be more:

• The default value of server.tomcat.internal-proxies shows {vbar} in both HTML and PDF reference instead of |
• The description of server.tomcat.relaxed-path-chars breaks the table formatting completely in the PDF version
• The description of server.tomcat.relaxed-query-chars breaks the table yet another time ;-)

It seems that neither of the escaping strategies work for both HTML and PDF. Luckily, the docs under https://asciidoctor.org/docs/user-manual/#escaping-the-cell-separator provide a third option.

The cell separator is controlled using the separator attribute on the table block. You’ll want to select a character that will never be used for content. A good candidate is the broken bar, or ¦

Applying this seems to fix the issues mentioned above.

Let me know what you think.
Cheers,
Christoph

[snicoll]

breaks the table formatting completely in the PDF version

@dreis2211 just to make sure I understand this one. I've generated a PDF from master (with your latest fix to include the appendices) and I don't see an obvious problem for the two keys you've mentioned. I can see the {vbar} though.

What have I missed?

[dreis2211]

Interesting. Now I can't reproduce this either anymore. I should have taken a screenshot. Maybe an error on my side by not (re-)compiling spring-boot-configuration-docs properly beforehand. Sorry for the confusion.

"At least" the {vbar} problem remains. But this gets me thinking if a simple escaping with \| might work after all. Give me a minute to try this.

[dreis2211]

@snicoll The simpler escaping with \| seems to work indeed. Could you give it another try whenever you have a spare minute, please?

[dreis2211]

Test failure seems related to changes in spring-projects/spring-kafka@e90d9e6