Require --config on cchost (#6694)

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Changed
 
 - All definitions in CCF's public headers are now under the `ccf::` namespace. Any application code which references any of these types directly (notably `StartupConfig`, `http_status`, `LoggerLevel`), they will now need to be prefixed with the `ccf::` namespace.
+- `cchost` now requires `--config`.
 
 ## [6.0.0-dev7]
 

src/host/main.cpp

@@ -80,9 +80,11 @@ int main(int argc, char** argv)
     "platforms) their value is captured in an attestation even if the "
     "configuration file itself is unattested.\n"};
 
-  std::string config_file_path = "config.json";
-  app.add_option(
-    "-c,--config", config_file_path, "Path to JSON configuration file");
+  std::string config_file_path;
+  app
+    .add_option(
+      "-c,--config", config_file_path, "Path to JSON configuration file")
+    ->required();
 
   ccf::ds::TimeString config_timeout = {"0s"};
   app.add_option(