Fix retrying failed m->d edits

The mutated event was being used as the error payload instead of the
original event, so it forgot that it was an edit.

docs/developer-orientation.md

@@ -93,7 +93,7 @@ Total transitive production dependencies: 137
 
 ### <font size="+2">🦕</font>
 
-* (31) better-sqlite3: SQLite3 is the best database, and this is the best library for it.
+* (31) better-sqlite3: SQLite is the best database, and this is the best library for it.
 * (27) @cloudrac3r/pug: Language for dynamic web pages. This is my fork. (I released code that hadn't made it to npm, and removed the heavy pug-filters feature.)
 * (16) stream-mime-type@1: This seems like the best option. Version 1 is used because version 2 is ESM-only.
 * (9) h3: Web server. OOYE needs this for the appservice listener, authmedia proxy, self-service, and more.

src/m2d/converters/event-to-message.js

@@ -546,7 +546,7 @@ async function eventToMessage(event, guild, di) {
 			if (!messageIDsToEdit.length) return
 
 			// Ok, it's an edit.
-			event.content = event.content["m.new_content"]
+			event = {...event, content: event.content["m.new_content"]}
 
 			// Is it editing a reply? We need special handling if it is.
 			// Get the original event, then check if it was a reply