Do not serialize empty values for state and pipe

Change-Id: I641774560d2465c2a85d74d5d5b6f312861ff539
diff --git a/Changes b/Changes
index 0b0f846..4dc1198 100644
--- a/Changes
+++ b/Changes
@@ -21,6 +21,7 @@
         - Return cursor position for query object (fixes #228; diewald)
         - Keep plugin state in statemanager (fixes #201; diewald)
         - Fix alerts in hint helper (diewald)
+        - Don't send empty pipes and states via query param (diewald)
 
 0.58 2024-11-15
         - Cookie path is settable now (hebasta)