[gn build] (manually) port 76a168b better

Author: nico

llvm/utils/gn/secondary/clang-tools-extra/clangd/test/BUILD.gn

@@ -29,7 +29,7 @@ write_lit_config("lit_site_cfg") {
 
     "CLANG_LIBS_DIR=",  # needed only for shared builds
     "CLANG_TOOLS_DIR=",
-    "CLANGD_ENABLE_REMOTE=",
+    "CLANGD_ENABLE_REMOTE=0",
     "LLVM_HOST_TRIPLE=$llvm_current_triple",
     "LLVM_LIT_TOOLS_DIR=",  # Intentionally empty, matches cmake build.
     "LLVM_TOOLS_DIR=" + rebase_path("$root_out_dir/bin"),