Add usage for check_existing

diff --git a/scripts/maint/updateFallbackDirs.py b/scripts/maint/updateFallbackDirs.py
index efa9bb49237cd0d292cbbce86d7b8eb26d90cdb9..ce837b480507b928db9ba16489ba6661149ba692 100755 (executable)
--- a/scripts/maint/updateFallbackDirs.py
+++ b/scripts/maint/updateFallbackDirs.py
@@ -1,6 +1,7 @@
 #!/usr/bin/python
 
 # Usage: scripts/maint/updateFallbackDirs.py > src/or/fallback_dirs.inc
+#        scripts/maint/updateFallbackDirs.py check_existing
 #
 # This script should be run from a stable, reliable network connection,
 # with no other network activity (and not over tor).