[etherpad-web] Update etherpad to the 1.7.5 release

[Andrea Veri <averi src gnome org>]

commit f3d44e0590f5f68b1b2a4d525e4531a247984741
Author: Andrea Veri <av gnome org>
Date:   Tue Jul 16 10:33:51 2019 +0000

    Update etherpad to the 1.7.5 release

 Dockerfile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/Dockerfile b/Dockerfile
index 9d4eb0a..eab13b8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 FROM centos:7
 MAINTAINER Wolfgang Kulhanek <WolfgangKulhanek gmail com>
-ARG ETHERPAD_VERSION="1.7.0"
+ARG ETHERPAD_VERSION="1.7.5"
 
 LABEL name="Etherpad Lite" \
       io.k8s.display-name="Etherpad Lite" \