[clangd-fuzzer] Update contruction of LSPServer.
[clangd-fuzzer] Update contruction of LSPServer.

The constructor for ClangdLSPServer changed in r318412 and r318925,
breaking the clangd-fuzzer build.

git-svn-id: a34e9779ed74578ad5922b3306b3d80a0c825546@320074 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra,llvm-mirror/clang-tools-extra