rpc: Treat all args after a hidden arg as hidden as well

This commit has no effect right now, but hardens the code for the future

src/rpc/util.cpp

@@ -504,7 +504,7 @@ std::string RPCHelpMan::ToString() const
     ret += m_name;
     bool was_optional{false};
     for (const auto& arg : m_args) {
-        if (arg.m_hidden) continue;
+        if (arg.m_hidden) break; // Any arg that follows is also hidden
         const bool optional = arg.IsOptional();
         ret += " ";
         if (optional) {
@@ -526,7 +526,7 @@ std::string RPCHelpMan::ToString() const
     Sections sections;
     for (size_t i{0}; i < m_args.size(); ++i) {
         const auto& arg = m_args.at(i);
-        if (arg.m_hidden) continue;
+        if (arg.m_hidden) break; // Any arg that follows is also hidden
 
         if (i == 0) ret += "\nArguments:\n";