优化

app/src/main/java/io/legado/app/model/webBook/SearchModel.kt

@@ -79,12 +79,13 @@ class SearchModel(private val scope: CoroutineScope, private val callBack: CallB
         }
         searchIndex++
         val source = bookSourceList[searchIndex]
+        searchPool?.let { searchPool ->
             val task = WebBook.searchBook(
                 scope,
                 source,
                 searchKey,
                 searchPage,
-            context = searchPool!!
+                context = searchPool
             ).timeout(30000L)
                 .onSuccess(searchPool) {
                     onSuccess(searchId, it)
@@ -94,6 +95,7 @@ class SearchModel(private val scope: CoroutineScope, private val callBack: CallB
                 }
             tasks.add(task)
         }
+    }
 
     @Synchronized
     private fun onSuccess(searchId: Long, items: ArrayList<SearchBook>) {