actually fix index bug

configure.py

diff --git a/configure.py b/configure.py
index 14ffa17..7a37659 100755
--- a/configure.py
+++ b/configure.py
@@ -48,7 +48,7 @@
         filler = False
         filler_id = 0
         for index in range(args.limit_num_projects):
-            if args.single != index:
+            if args.single >= 0 and args.single != index:
                 continue
 
             try: