Fix sign lazy initialisation

Fixes PaperMC/Paper#4975

Spigot-Server-Patches/API-to-get-a-BlockState-without-a-snapshot.patch

@@ -130,23 +130,6 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      }
  
      private T createSnapshot(T tileEntity) {
-diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java b/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
---- a/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
-+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
-@@ -0,0 +0,0 @@ public class CraftSign extends CraftBlockEntityState<TileEntitySign> implements
- 
-     public CraftSign(final Block block) {
-         super(block, TileEntitySign.class);
-+        if (lines == null) { lines = new String[]{"", "", "", ""}; } // Paper
-     }
- 
-     public CraftSign(final Material material, final TileEntitySign te) {
-         super(material, te);
-+        if (lines == null) { lines = new String[]{"", "", "", ""}; } // Paper
-     }
- 
-     @Override
 diff --git a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java