JSON API: Only do the work on GET requests.

src/generators/json_api.cpp

@@ -72,6 +72,12 @@ int main(int /*argc*/, char * /*argv*/[])
 
     cout << "Content-Type: application/json\r\n\r\n";
 
+    char *env{getenv("REQUEST_METHOD")};
+    if (env != nullptr && string(env) != "GET")
+    {
+        return 0;
+    }
+
     git::init(true);
 
     bool remove_lockfile{false};