Match update repo pattern at end of line

There is false-positive match with updates.mirantis.com system class

PROD-36466

Change-Id: Ibb44b743c936fbca198a4d1015d8198a3f0de2df
diff --git a/upgrade-mcp-release.groovy b/upgrade-mcp-release.groovy
index a6f609e..0510dfd 100644
--- a/upgrade-mcp-release.groovy
+++ b/upgrade-mcp-release.groovy
@@ -714,7 +714,7 @@
                     salt.cmdRun(venvPepper, 'I@salt:master', "cd /srv/salt/reclass/classes/cluster/$cluster_name && " +
                         "grep -r --exclude-dir=aptly -l 'system.linux.system.repo.mcp.contrail' * | xargs --no-run-if-empty sed -i 's/system.linux.system.repo.mcp.contrail/system.linux.system.repo.mcp.apt_mirantis.contrail/g'")
                     salt.cmdRun(venvPepper, 'I@salt:master', "cd /srv/salt/reclass/classes/cluster/$cluster_name && " +
-                        "grep -r --exclude-dir=aptly -l 'system.linux.system.repo.mcp.updates' * | xargs --no-run-if-empty sed -i 's/system.linux.system.repo.mcp.updates/system.linux.system.repo.mcp.apt_mirantis.update/g'")
+                        "grep -r --exclude-dir=aptly -l 'system.linux.system.repo.mcp.updates\$' * | xargs --no-run-if-empty sed -i 's/system.linux.system.repo.mcp.updates\$/system.linux.system.repo.mcp.apt_mirantis.update/g'")
                     salt.cmdRun(venvPepper, 'I@salt:master', "cd /srv/salt/reclass/classes/cluster/$cluster_name && " +
                         "grep -r --exclude-dir=aptly -l 'system.linux.system.repo.mcp.extra' * | xargs --no-run-if-empty sed -i 's/system.linux.system.repo.mcp.extra/system.linux.system.repo.mcp.apt_mirantis.extra/g'")