[Glitch] Center the text itself in upload area

Port a52ccd7ad9 to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/styles/components/misc.scss

@@ -1628,6 +1628,7 @@ button.icon-button.active i.fa-retweet {
   display: flex;
   align-items: center;
   justify-content: center;
+  text-align: center;
   color: $secondary-text-color;
   font-size: 18px;
   font-weight: 500;