dom0: minor qvm-sync-clock fix

Catch any error in vm.run, to not break clock syncing of all VMs because one
VM.

dom0/qvm-tools/qvm-sync-clock

@@ -91,7 +91,8 @@ def main():
                 print >> sys.stderr, '--> Syncing \'%s\' clock.' % vm.name
             try:
                 vm.run('root:date -u -s "%s"' % date_out, verbose=verbose)
-            except NotImplementedError:
+            except Exception as e:
+                print >> sys.stderr, "ERROR syncing time in VM '%s': %s" % (vm.name, str(e))
                 pass
 
 main()