update noVNC to v1.2.0

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/novnc b/novnc
index 9fe2fd04d4eeda0d5a360009453861803ba0ca84..9142f8f0f7b4a53447f5cfec3a797cbf0d6204a9 160000 (submodule)
--- a/novnc
+++ b/novnc
@@ -1 +1 @@
-Subproject commit 9fe2fd04d4eeda0d5a360009453861803ba0ca84
+Subproject commit 9142f8f0f7b4a53447f5cfec3a797cbf0d6204a9