Copying & pasting since PR #34745 results in a "null" being pasted

[wyattoday]

Description

Since PR #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

ee33488

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

[wxiaoguang]

Oops, I made a mistake, will fix

[wxiaoguang]

-> Fix readme path and markdown link paste #34755