domain: Remove the description/title hotplug hacks

We would unconditionally read VM description/hotplug from the inactive
domain XML, this allowed us to emulate metadata hotplug where it wasn't
implemented. However this means we end up doing many needless XMLDesc
calls, which slows down connection startup for low latency connections.

Since SetMetadata has been in libvirt for 2 years now, drop this hack.

virtManager/domain.py

@@ -960,9 +960,6 @@ class vmmDomain(vmmLibvirtObject):
                 self._backend.setMaxMemory(val)
 
         def _hotplug_metadata(val, mtype):
-            if not self.conn.check_support(
-                self.conn.SUPPORT_DOMAIN_SET_METADATA, self._backend):
-                return
             flags = (libvirt.VIR_DOMAIN_AFFECT_LIVE |
                      libvirt.VIR_DOMAIN_AFFECT_CONFIG)
             self._backend.setMetadata(mtype, val, None, None, flags)
@@ -1097,12 +1094,9 @@ class vmmDomain(vmmLibvirtObject):
         return self.get_name()
 
     def get_title(self):
-        return self.get_xmlobj(inactive=True).title
-
+        return self.get_xmlobj().title
     def get_description(self):
-        # Always show the inactive <description>, let's us fake hotplug
-        # for a field that's strictly metadata
-        return self.get_xmlobj(inactive=True).description
+        return self.get_xmlobj().description
 
     def get_memory(self):
         return int(self.get_xmlobj().memory)