Fix duplicate entries in source migration. Closes #1190

app/src/main/java/eu/kanade/tachiyomi/ui/migration/MigrationPresenter.kt

@@ -37,7 +37,7 @@ class MigrationPresenter(
     override fun onCreate(savedState: Bundle?) {
         super.onCreate(savedState)
 
-        db.getLibraryMangas()
+        db.getFavoriteMangas()
                 .asRxObservable()
                 .observeOn(AndroidSchedulers.mainThread())
                 .doOnNext { state = state.copy(sourcesWithManga = findSourcesWithManga(it)) }
@@ -148,4 +148,4 @@ class MigrationPresenter(
             db.updateMangaFavorite(manga).executeAsBlocking()
         }
     }
-}
+}