Refactor/unify path to `gerrit.config`
diff --git a/gerrit/Dockerfile.entrypoint-unprivileged b/gerrit/Dockerfile.entrypoint-unprivileged
index b9951b8..159860a 100644
--- a/gerrit/Dockerfile.entrypoint-unprivileged
+++ b/gerrit/Dockerfile.entrypoint-unprivileged
@@ -2,20 +2,22 @@
 
 set -e
 
+config=/var/gerrit/etc/gerrit.config
+
 {
-    git config -f /var/gerrit/etc/gerrit.config --unset-all auth.trustedOpenID || true
-    git config -f /var/gerrit/etc/gerrit.config --add auth.trustedOpenID https://
-    git config -f /var/gerrit/etc/gerrit.config --add auth.trustedOpenID imported:
+    git config -f ${config} --unset-all auth.trustedOpenID || true
+    git config -f ${config} --add auth.trustedOpenID https://
+    git config -f ${config} --add auth.trustedOpenID imported:
 }
 
 if [ "${GITHUB_OAUTH_CLIENT_ID}" -a "${GITHUB_OAUTH_CLIENT_SECRET}" ]; then
-    git config -f /var/gerrit/etc/gerrit.config \
+    git config -f ${config} \
         plugin.gerrit-oauth-provider-github-oauth.root-url "https://github.com/"
-    git config -f /var/gerrit/etc/gerrit.config \
+    git config -f ${config} \
         plugin.gerrit-oauth-provider-github-oauth.client-id "${GITHUB_OAUTH_CLIENT_ID}"
-    git config -f /var/gerrit/etc/gerrit.config \
+    git config -f ${config} \
         plugin.gerrit-oauth-provider-github-oauth.client-secret "${GITHUB_OAUTH_CLIENT_SECRET}"
-    git config -f /var/gerrit/etc/gerrit.config --add auth.trustedOpenID github-oauth:
+    git config -f ${config} --add auth.trustedOpenID github-oauth:
 fi
 
 secret=/var/gerrit/passwd/secret
@@ -30,13 +32,13 @@
 if [ "${GERRIT_USER_EMAIL}" ]; then
     passwd=$(cat ${secret})
 
-    git config -f /etc/gerrit/gerrit.config user.email ${GERRIT_USER_EMAIL}
-    git config -f /etc/gerrit/gerrit.config sendemail.smtpServer mail.${SA_PUBLIC_DOMAIN_NAME}
-    git config -f /etc/gerrit/gerrit.config sendemail.smtpServerPort 465
-    git config -f /etc/gerrit/gerrit.config sendemail.smtpEncryption ssl
-    git config -f /etc/gerrit/gerrit.config sendemail.smtpUser ${GERRIT_USER_EMAIL}
-    git config -f /etc/gerrit/gerrit.config sendemail.smtpPass ${passwd}
-    git config -f /etc/gerrit/gerrit.config sendemail.html false
+    git config -f ${config} user.email ${GERRIT_USER_EMAIL}
+    git config -f ${config} sendemail.smtpServer mail.${SA_PUBLIC_DOMAIN_NAME}
+    git config -f ${config} sendemail.smtpServerPort 465
+    git config -f ${config} sendemail.smtpEncryption ssl
+    git config -f ${config} sendemail.smtpUser ${GERRIT_USER_EMAIL}
+    git config -f ${config} sendemail.smtpPass ${passwd}
+    git config -f ${config} sendemail.html false
 fi
 
 exec /entrypoint.sh "$@"