update etherpad module.

diff --git a/mod/etherpad b/mod/etherpad
index 22007e7cbe1eb196346f1a1fa7222f28b1592e63..6e892127767ccaed1c57df4a281d11ad976935ea 160000 (submodule)
--- a/mod/etherpad
+++ b/mod/etherpad
@@ -1 +1 @@
-Subproject commit 22007e7cbe1eb196346f1a1fa7222f28b1592e63
+Subproject commit 6e892127767ccaed1c57df4a281d11ad976935ea