Revert "Add "System theme" option to widgets" (#753)

app/src/main/res/values-de/strings.xml

@@ -326,7 +326,6 @@
     <string name="widget_timetable_theme_title">Thema wählen</string>
     <string name="widget_timetable_theme_light">Licht</string>
     <string name="widget_timetable_theme_dark">Dunkel</string>
-    <string name="widget_timetable_theme_system">Systemthema</string>
 
 
     <!--Preferences-->

app/src/main/res/values-pl/strings.xml

@@ -351,7 +351,6 @@
     <string name="widget_timetable_theme_title">Wybierz motyw</string>
     <string name="widget_timetable_theme_light">Jasny</string>
     <string name="widget_timetable_theme_dark">Ciemny</string>
-    <string name="widget_timetable_theme_system">Motyw systemu</string>
 
 
     <!--Preferences-->

app/src/main/res/values-ru/strings.xml

@@ -348,7 +348,6 @@
     <string name="widget_timetable_theme_title">Выбрать тему</string>
     <string name="widget_timetable_theme_light">Светлая</string>
     <string name="widget_timetable_theme_dark">Тёмная</string>
-    <string name="widget_timetable_theme_system">Системная тема</string>
 
 
     <!--Preferences-->

app/src/main/res/values-uk/strings.xml

@@ -349,7 +349,6 @@
     <string name="widget_timetable_theme_title">Вибрати тему</string>
     <string name="widget_timetable_theme_light">Світла</string>
     <string name="widget_timetable_theme_dark">Темна</string>
-    <string name="widget_timetable_theme_system">Тема системи</string>
 
 
     <!--Preferences-->

app/src/main/res/values/strings.xml

@@ -336,7 +336,6 @@
     <string name="widget_timetable_theme_title">Choose theme</string>
     <string name="widget_timetable_theme_light">Light</string>
     <string name="widget_timetable_theme_dark">Dark</string>
-    <string name="widget_timetable_theme_system">System Theme</string>
 
 
     <!--Preferences-->