Remove isons_as_buttons from themes

theme/default/theme.json

@@ -2,7 +2,6 @@
     "verified-site-color": "lightgreen",
     "newswire-publish-icon": "True",
     "full-width-timeline-buttons": "False",
-    "icons-as-buttons": "False",
     "rss-icon-at-top": "True",
     "publish-button-at-top": "False",
     "search-banner-height": "30vh",