Make sure that the InputHandler reference is not null (#85)

Closes #84.

Author: PrashantMohta

Assembly-CSharp/Patches/UIButtonSkins.cs

@@ -15,8 +15,8 @@ public class UIButtonSkins : global::UIButtonSkins
         [MonoModIgnore]
         private extern ButtonSkin GetButtonSkinFor(string buttonName);
         [MonoModIgnore]
-        private extern ButtonSkin GetButtonSkinFor(InputControlType inputControlType);
-        [MonoModIgnore]
+        private extern ButtonSkin orig_GetButtonSkinFor(InputControlType inputControlType);
+        
         private InputHandler ih;
 
         public extern void orig_RefreshKeyMappings();
@@ -94,6 +94,14 @@ public IEnumerator ShowCurrentButtonMappings()
             while (enumerator.MoveNext()) yield return enumerator.Current;
             yield break;
         }
+        
+        private ButtonSkin GetButtonSkinFor(InputControlType inputControlType)
+	    {
+            if(this.ih == null){
+                this.ih = (Modding.Patches.InputHandler)InputHandler.Instance;
+            }
+            return orig_GetButtonSkinFor(inputControlType);
+        }
 
         private void SetupRefs()
         {