[clang-format] Fix comment indentation in text protos

Summary: This patch fixes a bug where the comment indent of comments in text protos gets messed up because by default paren states get created with AlignColons = true (which makes snese for ObjC).

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D43194

llvm-svn: 324896