Pin python-pymysql latest version MOS repo.

Change-Id: Ia42b38284331484df7bafe80773b7f5e1b28fd01
diff --git a/glance/control/cluster.yml b/glance/control/cluster.yml
index 6402721..bb87f16 100644
--- a/glance/control/cluster.yml
+++ b/glance/control/cluster.yml
@@ -4,6 +4,12 @@
 - service.haproxy.proxy.single
 - system.haproxy.proxy.listen.openstack.glance
 parameters:
+  linux:
+    system:
+      package:
+        python-pymysql:
+          fromrepo: ${_param:openstack_version}
+          version: latest
   glance:
     server:
       enabled: true