Remove condition causing infinite looping in unit tests

Clocker/Overall App/Themer.swift

@@ -50,14 +50,11 @@ class Themer: NSObject {
                                                           object: nil)
 
         if #available(macOS 10.14, *) {
-            effectiveApperanceObserver = NSApp.observe(\.effectiveAppearance) { [weak self] _, _ in
-                if let sSelf = self {
-                    sSelf.setAppAppearance()
+            effectiveApperanceObserver = NSApp.observe(\.effectiveAppearance) { _, _ in
                 NotificationCenter.default.post(name: .themeDidChangeNotification, object: nil)
             }
         }
     }
-    }
 }
 
 extension Themer {
@@ -452,9 +449,11 @@ extension Themer {
             } else if themeIndex == .system {
                 appAppearance = retrieveCurrentSystem() == .dark ? NSAppearance(named: .darkAqua) : NSAppearance(named: .aqua)
             }
+            if NSApp.appearance != appAppearance {
                 NSApp.appearance = appAppearance
             }
         }
+    }
 
     private func fallbackImageProvider(_ lightImage: NSImage,
                                        _ darkImage: NSImage,