[Etherpad] Disable obsolete plugins countable and table

pica-etherpad/Dockerfile

@@ -8,10 +8,10 @@ FROM base as downloader
 ARG ETHERPAD_VERSION_BUILD=1.8.4
 ARG ETHERPAD_PLUGINS="\
   ep_adminpads2 ep_align ep_author_hover ep_back_button ep_chatdate \
-  ep_comments_page ep_countable ep_delete_after_delay ep_delete_empty_pads ep_font_color \
+  ep_comments_page ep_delete_after_delay ep_delete_empty_pads ep_font_color \
   ep_font_family ep_headings2 ep_markdown ep_message_all ep_pad_activity_nofication_in_title \
   ep_pads_stats ep_prompt_for_name ep_set_title_on_pad \
-  ep_subscript_and_superscript ep_tables3"
+  ep_subscript_and_superscript"
 
 RUN apt-get update && \
     apt-get install -y \