fix negated custom sprite check + prepare for 1.2.16

Author: catapillie

Code/Entities/PurpleBooster.cs

@@ -58,7 +58,7 @@ public PurpleBooster(Vector2 position, string spriteOverride)
     {
         this.Depth = Depths.Above;
         this.Collider = new Circle(10f, 0f, 2f);
-        if (string.IsNullOrWhiteSpace(spriteOverride))
+        if (!string.IsNullOrWhiteSpace(spriteOverride))
         {
             spriteOverride = spriteOverride.Trim().TrimEnd('/') + "/";
             this.sprite = new Sprite(GFX.Game, spriteOverride);

everest.yaml

@@ -1,5 +1,5 @@
 - Name: VortexHelper
-  Version: 1.2.15
+  Version: 1.2.16
   DLL: Code/bin/VortexHelper.dll
   Dependencies:
     - Name: EverestCore