Ignore errors from adding a reaction with reactOnSeen

src/data/Thread.js

@@ -325,7 +325,7 @@ class Thread {
     }
 
     if (config.reactOnSeen) {
-      await msg.addReaction(config.reactOnSeenEmoji);
+      await msg.addReaction(config.reactOnSeenEmoji).catch(utils.noop);
     }
 
     // Interrupt scheduled closing, if in progress

src/utils.js

@@ -310,13 +310,12 @@ function disableCodeBlocks(str) {
   return str.replace(/`/g, "`\u200b");
 }
 
-/**
- *
- */
 function readMultilineConfigValue(str) {
   return Array.isArray(str) ? str.join("\n") : str;
 }
 
+function noop() {}
+
 module.exports = {
   BotError,
 
@@ -355,4 +354,6 @@ module.exports = {
   disableCodeBlocks,
 
   readMultilineConfigValue,
+
+  noop,
 };