[gimp-web/oscp] Land ca-certificates as well

[Andrea Veri <averi src gnome org>]

commit 4fcf2128c032c6d525cd20c0175b775353220176
Author: Andrea Veri <averi redhat com>
Date:   Wed Sep 8 12:53:37 2021 +0200

    Land ca-certificates as well

 testing.docs.gimp.org/docs_build/Dockerfile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/testing.docs.gimp.org/docs_build/Dockerfile b/testing.docs.gimp.org/docs_build/Dockerfile
index 16d22d30..1ac6263d 100644
--- a/testing.docs.gimp.org/docs_build/Dockerfile
+++ b/testing.docs.gimp.org/docs_build/Dockerfile
@@ -3,7 +3,8 @@ USER root
 
 RUN apt-get update && apt-get install -y --no-install-recommends \ 
     automake build-essential docbook-xml docbook-xsl pkg-config \
-    pngcrush pngnq python3 python3-libxml2 xsltproc gettext git 
+    pngcrush pngnq python3 python3-libxml2 xsltproc gettext git \
+    ca-certificates 
 
 RUN groupadd gimpdocs -g 1000580000 && \
     useradd gimpdocs -g 1000580000 -u 1000580000 -r -l -m