Same mistake
I did the same thing...what did you do to get the stock mms.apk back on your phone?
You can remove it with root as described above. I wouldn't do it though. Others mentioned in a number of posts that it's needed for other messengers to function.
I can confirm. Removing mms.apk will cause you to lose functionality. You will be able to send and recieve regular texts, but multimedia (pics, vids) will no longer appear when sent to the phone... Consider my findings a "D'oh" moment.
I did the same thing...what did you do to get the stock mms.apk back on your phone?