Fix emoji replacing some chars

[sampaiodiego]

The new emoji picker is causing this weird behavior:

Also, I've optimized the sprites (forgot to do that on the initial PR 😬 ):

# before
$ ls -lh public/packages/emojione
total 13M
-rw-rw-r-- 1 myself myself 1,6M mai 20 16:48 activity-sprites.png
-rw-rw-r-- 1 myself myself 911K mai 20 16:48 flags-sprites.png
-rw-rw-r-- 1 myself myself 637K mai 20 16:48 food-sprites.png
-rw-rw-r-- 1 myself myself 8,5K mai 20 16:48 modifier-sprites.png
-rw-rw-r-- 1 myself myself 1,1M mai 20 16:48 nature-sprites.png
-rw-rw-r-- 1 myself myself 893K mai 20 16:48 objects-sprites.png
-rw-rw-r-- 1 myself myself 6,0M mai 20 16:48 people-sprites.png
-rw-rw-r-- 1 myself myself  36K mai 20 16:48 regional-sprites.png
-rw-rw-r-- 1 myself myself 807K mai 20 16:48 symbols-sprites.png
-rw-rw-r-- 1 myself myself 579K mai 20 16:48 travel-sprites.png

# then
$ ls -lh public/packages/emojione
total 7,0M
-rw-rw-r-- 1 myself myself 818K mai 20 16:49 activity-sprites.png
-rw-rw-r-- 1 myself myself 455K mai 20 16:49 flags-sprites.png
-rw-rw-r-- 1 myself myself 405K mai 20 16:49 food-sprites.png
-rw-rw-r-- 1 myself myself 4,3K mai 20 16:49 modifier-sprites.png
-rw-rw-r-- 1 myself myself 644K mai 20 16:49 nature-sprites.png
-rw-rw-r-- 1 myself myself 540K mai 20 16:49 objects-sprites.png
-rw-rw-r-- 1 myself myself 3,3M mai 20 16:49 people-sprites.png
-rw-rw-r-- 1 myself myself  21K mai 20 16:49 regional-sprites.png
-rw-rw-r-- 1 myself myself 468K mai 20 16:49 symbols-sprites.png
-rw-rw-r-- 1 myself myself 333K mai 20 16:49 travel-sprites.png