fix: Reset last upload path when it doesn't exist anymore

Signed-off-by: Álvaro Brey <alvaro.brey@nextcloud.com>

app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java

@@ -263,10 +263,15 @@ public class ReceiveExternalFilesActivity extends FileActivity
             startSyncFolderOperation(fileByPath);
             populateDirectoryList();
         } else {
-            browseToRoot();
+            handleNonExistingFolder();
         }
     }
 
+    private void handleNonExistingFolder() {
+        browseToRoot();
+        preferences.setLastUploadPath(OCFile.ROOT_PATH);
+    }
+
     @Override
     protected void onSaveInstanceState(@NonNull Bundle outState) {
         Log_OC.d(TAG, "onSaveInstanceState() start");
@@ -635,7 +640,7 @@ public class ReceiveExternalFilesActivity extends FileActivity
                 startSyncFolderOperation(fileByPath);
                 populateDirectoryList();
             } else {
-                browseToRoot();
+                handleNonExistingFolder();
             }
         }
     }