Minor cleanup

(cherry picked from commit 9a75232ca4)

# Conflicts:
#	app/src/main/java/eu/kanade/presentation/browse/SourcesScreen.kt
#	app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/SourcesFilterController.kt

app/src/main/java/eu/kanade/domain/source/interactor/ToggleLanguage.kt

@@ -9,8 +9,8 @@ class ToggleLanguage(
 ) {
 
     fun await(language: String) {
-        val isEnabled = language in preferences.enabledLanguages().get()
-        if (isEnabled) {
+        val enabled = language in preferences.enabledLanguages().get()
+        if (enabled) {
             preferences.enabledLanguages() -= language
         } else {
             preferences.enabledLanguages() += language