Fix NPE when suffocating in ME Drives

And hopefully all other cases related to missing slot states
Closes #420

src/main/java/appeng/client/render/model/DriveBakedModel.java

@@ -60,6 +60,9 @@ public class DriveBakedModel implements IBakedModel {
             }
 
             DriveSlotsState slotsState = extState.getValue(BlockDrive.SLOTS_STATE);
+            if (slotsState == null) {
+                return result;
+            }
 
             for (int row = 0; row < 5; row++) {
                 for (int col = 0; col < 2; col++) {
@@ -90,6 +93,7 @@ public class DriveBakedModel implements IBakedModel {
             }
         }
 
+
         return result;
     }