Assume enforce secure chat as false by default

Setting it to true will result in chat validation errors on the client for other players without chat sessions or valid signatures

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/rewriter/EntityPacketRewriter1_20_5.java

@@ -210,9 +210,15 @@ public final class EntityPacketRewriter1_20_5 extends EntityRewriter<Clientbound
                 handler(playerTrackerHandler());
                 handler(wrapper -> {
                     // Enforces secure chat - moved from server data (which is unfortunately sent a while after this)
-                    // Just put in what we know if this is sent multiple times
                     final AcknowledgedMessagesStorage storage = wrapper.user().get(AcknowledgedMessagesStorage.class);
+                    if (storage.secureChatEnforced() != null) {
+                        // Just put in what we know if this is sent multiple times
                         wrapper.write(Type.BOOLEAN, storage.isSecureChatEnforced());
+                    } else {
+                        // Assume that it isn't, otherwise the client will disregard chat messages from players
+                        // without chat sessions if it assumes secure chat is enforced
+                        wrapper.write(Type.BOOLEAN, false);
+                    }
 
                     storage.clear();