Fix crash with disconnecting the world.

Signed-off-by: shedaniel <daniel@shedaniel.me>

gradle.properties

@@ -1,5 +1,5 @@
 org.gradle.jvmargs=-Xmx3G
-mod_version=4.6.0
+mod_version=4.6.1
 supported_version=1.16.x
 minecraft_version=1.16.1
 yarn_version=1.16.1+build.4+legacy.20w09a+build.8

src/main/java/me/shedaniel/rei/gui/widget/EntryListWidget.java

@@ -580,7 +580,7 @@ public class EntryListWidget extends WidgetWithBounds {
                 if (widget.mouseReleased(mouseX, mouseY, button))
                     return true;
             ClientPlayerEntity player = minecraft.player;
-            if (ClientHelper.getInstance().isCheating() && !player.inventory.getCursorStack().isEmpty() && RoughlyEnoughItemsCore.canDeleteItems()) {
+            if (ClientHelper.getInstance().isCheating() && player.inventory != null && !player.inventory.getCursorStack().isEmpty() && RoughlyEnoughItemsCore.canDeleteItems()) {
                 ClientHelper.getInstance().sendDeletePacket();
                 return true;
             }