clang-format: Fix documentation generation
It seems that the changes done to ClangFormatStyleOptions.rst @334408 are causing the generation of the documentation to fail, with the following error:
Warning, treated as error: /llvm/tools/clang/docs/ClangFormatStyleOptions.rst:1060: WARNING: Definition list ends without a blank line; unexpected unindent.
This is due to missing indent in some code block, and fixed by this patch.
Reviewers: krasimir, djasper, klimek
Reviewed By: krasimir
Differential Revision: https://reviews.llvm.org/D48161