[clang-format][docs] fix indentation of rst code block

[HazardyKnusperkeks]

Hi, thanks for you contribution.

But the rst is generated by a script, the error is in Format.h.

And we already have a review for an even broader fix: D112572.

[MyDeveloperDay]

This should be Format.h, didn't we recently fix this?

[HazardyKnusperkeks]

In D112664#3101142, @MyDeveloperDay wrote:

This should be Format.h, didn't we recently fix this?

Yes we did, this is from before. :) So it is now obsolete.

clang/docs/ClangFormatStyleOptions.rst

**SpacesInLineCommentPrefix** (``SpacesInLineComment``) :versionbadge:`clang-format 14`
   Maximum = 0
   //Forces to start every comment directly after the slashes
 
   Note that in line comment sections the relative indent of the subsequent
   lines is kept, that means the following:
 
   .. code-block:: c++
 
      before:                                   after:
      Minimum: 1
      //if (b) {                                // if (b) {
      //  return true;                          //   return true;
      //}                                       // }
 
      Maximum: 0
      /// List:                                 ///List:
      ///  - Foo                                /// - Foo
      ///    - Bar                              ///   - Bar
 
   Nested configuration flags:
 
 
   * ``unsigned Minimum`` The minimum number of spaces at the start of the comment.
 
   * ``unsigned Maximum`` The maximum number of spaces at the start of the comment.