Removed more uses of ?.
Removed more uses of ?.

--- a/KerbalEngineer.Unity/Setting.cs
+++ b/KerbalEngineer.Unity/Setting.cs
@@ -78,7 +78,8 @@
 
         protected virtual void Update()
         {
-            m_OnUpdate?.Invoke();
+            if (m_OnUpdate != null)
+                m_OnUpdate.Invoke();
         }
 
         private static void SetButton(GameObject buttonObject, UnityAction onClick)

--- a/KerbalEngineer.Unity/UI/StyleApplicator.cs
+++ b/KerbalEngineer.Unity/UI/StyleApplicator.cs
@@ -100,7 +100,8 @@
         {
             SetSelectable(textStyle, normal, highlight, pressed, disabled);
 
-            Image toggleImage = GetComponent<Toggle>()?.graphic as Image;
+            Toggle toggle = GetComponent<Toggle>();
+            Image toggleImage = (toggle != null) ? toggle.graphic as Image : null;
             if (toggleImage != null)
             {
                 toggleImage.sprite = pressed;

--- a/KerbalEngineer.Unity/UI/Window.cs
+++ b/KerbalEngineer.Unity/UI/Window.cs
@@ -159,7 +159,8 @@
                 yield return null;
             }
 
-            callback?.Invoke();
+            if (callback != null)
+                callback.Invoke();
 
             m_ScaleFadeCoroutine = null;
         }