Merge pull request #2311 from 821938089/little-fix

修复订阅源调试没有输出的问题

app/src/main/java/io/legado/app/ui/rss/source/debug/RssSourceDebugModel.kt

@@ -29,6 +29,7 @@ class RssSourceDebugModel(application: Application) : BaseViewModel(application)
 
     fun startDebug(source: RssSource) {
         execute {
+            Debug.callback = this@RssSourceDebugModel
             Debug.startDebug(this, source)
         }
     }