Verify high-availability formatting using GJF 1.7

Change I216f69ea set the default formatting version to GJF 1.24.0,
however older branches of the high-availability plugin are still
formatted with GJF 1.7.

Explicitly set the GJF version to 1.7 so that we can still have
successful validation for older branches.

Change-Id: I0ab64aec1711ee8345cd800fb554d75287652d7c

Jenkinsfile

diff --git a/Jenkinsfile b/Jenkinsfile
index 0c516ca..2323d5d 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -1,2 +1,3 @@
 pluginPipeline(formatCheckId: 'gerritforge:plugins-high-availability-code-style',
-               buildCheckId: 'gerritforge:plugins-high-availability-build-test')
+               buildCheckId: 'gerritforge:plugins-high-availability-build-test',
+               gjfVersion: '1.7')