Fix typo

uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/list/ListHabitsActivity.kt

@@ -82,7 +82,7 @@ class ListHabitsActivity : AppCompatActivity(), Preferences.Listener {
 
     override fun onPause() {
         midnightTimer.onPause()
-        screen.onDettached()
+        screen.onDetached()
         adapter.cancelRefresh()
         super.onPause()
     }

uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/list/ListHabitsScreen.kt

@@ -101,7 +101,7 @@ class ListHabitsScreen
         commandRunner.addListener(this)
     }
 
-    fun onDettached() {
+    fun onDetached() {
         commandRunner.removeListener(this)
     }