Fix _get_active_tmpfile to handle local file GIs.

av98.py

@@ -808,6 +808,8 @@ Slow internet connection?  Use 'set timeout' to be more patient.""")
     def _get_active_tmpfile(self):
         if self.mime == "text/gemini":
             return self.idx_filename
+        elif self.gi.scheme == "file":
+            return self.gi.path
         else:
             return self.tmp_filename