Removed the copy-constructor of JsonDocument (issue #1189)

extras/tests/Misc/Issue1189.cpp

@@ -0,0 +1,13 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2020
+// MIT License
+
+#include <ArduinoJson.h>
+
+// a function should not be able to get a JsonDocument by value
+void f(JsonDocument) {}
+
+int main() {
+  DynamicJsonDocument doc(1024);
+  f(doc);
+}