Remove redundant DB call in library settings (closes #3128)

(cherry picked from commit 521ebf0678)

# Conflicts:
#	app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt

app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestoreService.kt

@@ -235,6 +235,10 @@ class BackupRestoreService : Service() {
 
         // Restore individual manga
         mangasJson.forEach {
+            if (job?.isActive != true) {
+                throw Exception(getString(R.string.restoring_backup_canceled))
+            }
+
             restoreManga(it.asJsonObject)
         }
 
@@ -275,10 +279,6 @@ class BackupRestoreService : Service() {
                     ?: JsonArray()
             )
 
-            if (job?.isActive != true) {
-                throw Exception(getString(R.string.restoring_backup_canceled))
-            }
-
             // EXH -->
             manga = EXHMigrations.migrateBackupEntry(manga)
             // <-- EXH

app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsLibraryController.kt

@@ -172,7 +172,7 @@ class SettingsLibraryController : SettingsController() {
             preference {
                 titleRes = R.string.action_edit_categories
 
-                val catCount = db.getCategories().executeAsBlocking().size
+                val catCount = dbCategories.size
                 summary = context.resources.getQuantityString(R.plurals.num_categories, catCount, catCount)
 
                 onClick {