During upgrade MCP Update system submodule first

Change-Id: I3ea5438dad90593e5342529602836520b45c58e5
Related-Prod: PROD-26982 (PROD:26982)
(cherry picked from commit d37e6fc732db958e11d622e50dbda0f14ebf06c5)
diff --git a/upgrade-mcp-release.groovy b/upgrade-mcp-release.groovy
index 24ac15f..b229134 100644
--- a/upgrade-mcp-release.groovy
+++ b/upgrade-mcp-release.groovy
@@ -172,6 +172,7 @@
                 if (updateClusterModel) {
                     common.infoMsg('Perform: UPDATE_CLUSTER_MODEL')
                     def dateTime = common.getDatetime()
+                    salt.cmdRun(venvPepper, 'I@salt:master', "cd /srv/salt/reclass/ && git submodule update")
                     salt.cmdRun(venvPepper, 'I@salt:master', "cd /srv/salt/reclass/classes/cluster/$cluster_name && " +
                         "grep -r --exclude-dir=aptly -l 'mcp_version: .*' * | xargs --no-run-if-empty sed -i 's|mcp_version: .*|mcp_version: \"$targetMcpVersion\"|g'")
                     // Do the same, for deprecated variable-duplicate