keep back compatibility between "=" and "{=}"

Author: facontidavide

include/behaviortree_cpp/tree_node.h

@@ -502,7 +502,7 @@ inline Result TreeNode::setOutput(const std::string& key, const T& value)
                                           key, "]"));
   }
   StringView remapped_key = remap_it->second;
-  if (remapped_key == "{=}")
+  if (remapped_key == "{=}" || remapped_key == "=")
   {
     config().blackboard->set(static_cast<std::string>(key), value);
     return {};

src/tree_node.cpp

@@ -394,7 +394,7 @@ StringView TreeNode::stripBlackboardPointer(StringView str)
 Expected<StringView> TreeNode::getRemappedKey(StringView port_name,
                                               StringView remapped_port)
 {
-  if (remapped_port == "{=}")
+  if (remapped_port == "{=}" || remapped_port == "=")
   {
     return {port_name};
   }