[clang-format] fix indent in alignChainedConditionals

Clang-format was indenting the lines following the `?` in the added test
case by +5 instead of +4. This only happens in a very specific
situation, where the `?` is followed by a multiline block comment, as in
the example. This fix addresses this without regressing any of the
existing tests.

Differential Revision: https://reviews.llvm.org/D101033