[etherpad-web/oscp-backend] Restore font_family and font_size plugins

[Bartłomiej Piotrowski <bpiotrowski src gnome org>]

commit f70c7fca59fb373e5c49ae8dace351cd82cc0eea
Author: Bartłomiej Piotrowski <bpiotrowski gnome org>
Date:   Wed May 13 13:33:04 2020 +0200

    Restore font_family and font_size plugins

 Dockerfile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/Dockerfile b/Dockerfile
index 59c980e..86342f3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -31,7 +31,9 @@ RUN npm install ep_adminpads \
     ep_headings2 \
     ep_font_color \
     ep_markdown \
-    ep_copy_paste_select_all
+    ep_copy_paste_select_all \
+    ep_font_family \
+    ep_font_size
 
 USER etherpad
 EXPOSE 9001