### Description Since PR https://github.com/go-gitea/gitea/pull/34745, copying and pasting from within an issue (to, for instance, quote and respond to a chunk of text) results in "null" being pasted. ### Gitea Version ee334886f31a664812b2a699f0be70753db944db ### Can you reproduce the bug on the Gitea demo site? Yes ### Log Gist _No response_ ### Screenshots _No response_ ### Git Version _No response_ ### Operating System _No response_ ### How are you running Gitea? Self built. ### Database None