cyclades: Fix bug in allocating archipelago VMs

This commit fixes a bug that caused backend allocator to send
archipelago VMs backends to backends not in ARCHIPELAGO_BACKENDS
setting. The flavor disk template is parsed before the backend
allocation, so the disk_template at this point is ext and not ext_vlmc,
as it was expected.

snf-cyclades-app/synnefo/logic/backend_allocator.py

@@ -105,7 +105,7 @@ def get_available_backends():
 
 
 def filter_archipelagos_backends(available_backends, disk_template):
-    if disk_template.startswith("ext_"):
+    if disk_template == "ext":
         available_backends = filter(lambda x: x.id in ARCHIPELAGO_BACKENDS,
                                     available_backends)
     else: