bugfix: change CANONICAL_WEB_URL's port to default 80 from 8080

Change CANONICAL_WEB_URL to http://$HOSTNAME. Because 80 is the
default web port. And according to the file docker-compose.yaml
mentioned in the github README, outside port 80 is mapped to 8080
inside the gerrit container.
So, directly remove 8080.

Signed-off-by: Daniel Tse <learningendless@gmail.com>
Change-Id: Ifcaf6712a3bfdbf2034dc28354bbe1754e29b82b
diff --git a/centos/7/Dockerfile b/centos/7/Dockerfile
index 732ff5f..01e5af3 100644
--- a/centos/7/Dockerfile
+++ b/centos/7/Dockerfile
@@ -24,6 +24,6 @@
 VOLUME ["/var/gerrit/git", "/var/gerrit/index", "/var/gerrit/cache", "/var/gerrit/db", "/var/gerrit/etc"]
 
 # Start Gerrit
-CMD git config -f /var/gerrit/etc/gerrit.config gerrit.canonicalWebUrl "${CANONICAL_WEB_URL:-http://$HOSTNAME:8080/}" && \
+CMD git config -f /var/gerrit/etc/gerrit.config gerrit.canonicalWebUrl "${CANONICAL_WEB_URL:-http://$HOSTNAME}" && \
     git config -f /var/gerrit/etc/gerrit.config noteDb.changes.autoMigrate true && \
         /var/gerrit/bin/gerrit.sh run
\ No newline at end of file
diff --git a/ubuntu/16/Dockerfile b/ubuntu/16/Dockerfile
index 0996aed..7405465 100644
--- a/ubuntu/16/Dockerfile
+++ b/ubuntu/16/Dockerfile
@@ -27,6 +27,6 @@
 VOLUME ["/var/gerrit/git", "/var/gerrit/index", "/var/gerrit/cache", "/var/gerrit/db", "/var/gerrit/etc"]
 
 # Start Gerrit
-CMD git config -f /var/gerrit/etc/gerrit.config gerrit.canonicalWebUrl "${CANONICAL_WEB_URL:-http://$HOSTNAME:8080/}" && \
+CMD git config -f /var/gerrit/etc/gerrit.config gerrit.canonicalWebUrl "${CANONICAL_WEB_URL:-http://$HOSTNAME}" && \
     git config -f /var/gerrit/etc/gerrit.config noteDb.changes.autoMigrate true && \
         /var/gerrit/bin/gerrit.sh run