fix attempt for downloader when only symlinx exists but not actual data file in the annex (#2)

UNFCCC_GHG_data/UNFCCC_downloader/download_non-annexI.py

@@ -96,7 +96,7 @@ for idx, submission in submissions.iterrows():
             os.remove(local_filename)
     
     # now we have removed error pages, so a present file should not be overwritten
-    if (not local_filename.exists()) or (not local_filename.is_symlink()):
+    if (not local_filename.exists()) and (not local_filename.is_symlink()):
         i = 0  # reset counter
         while not local_filename.exists() and i < 10:
             # for i = 0 and i = 5 try to get a new session ID