Fixed present window getter.

Author: ivanvorobei

Example App/SPAlert.xcodeproj/project.xcworkspace/xcuserdata/ivanvorobei.xcuserdatad/UserInterfaceState.xcuserstate

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name = 'SPAlert'
-  s.version = '3.0.8'
+  s.version = '3.0.9'
   s.summary = 'Native alert from Apple Music & Feedback. Contains Done, Heart & Message and other presets.'
   s.homepage = 'https://github.com/ivanvorobei/SPAlert'
   s.source = { :git => 'https://github.com/ivanvorobei/SPAlert.git', :tag => s.version }

SPAlert.podspec

@@ -58,7 +58,7 @@ open class SPAlertView: UIView {
         return view
     }()
 
-    weak open var presentWindow: UIWindow? = UIApplication.shared.windows.first
+    weak open var presentWindow: UIWindow?
 
     // MARK: - Init
 
@@ -157,7 +157,13 @@ open class SPAlertView: UIView {
     }
 
     open func present(duration: TimeInterval = 1.5, haptic: SPAlertHaptic = .success, completion: (() -> Void)? = nil) {
+        
+        if self.presentWindow == nil {
+            self.presentWindow = UIApplication.shared.windows.first
+        }
+        
         guard let window = self.presentWindow else { return }
+        
         window.addSubview(self)
 
         // Prepare for present