Unable to fetch author user in emojiMod

[kristersd]

We still have rare occasions where emojiMod fails. We are unable to fetch the original message author. We should handle this case gracefully, using getMessage from our helpers.

[ERROR] Unknown Member DiscordAPIError[10007]: Unknown Member
    at handleErrors (/build/reactibot/node_modules/@discordjs/rest/dist/index.js:748:13)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async SequentialHandler.runRequest (/build/reactibot/node_modules/@discordjs/rest/dist/index.js:1149:23)
    at async SequentialHandler.queueRequest (/build/reactibot/node_modules/@discordjs/rest/dist/index.js:980:14)
    at async _REST.request (/build/reactibot/node_modules/@discordjs/rest/dist/index.js:1293:22)
    at async GuildMemberManager._fetchSingle (/build/reactibot/node_modules/discord.js/src/managers/GuildMemberManager.js:222:18)
    at async Promise.all (index 1)
    at async Object.handleReaction (file:///build/reactibot/dist/features/emojiMod.js:105:53)