Arthur: update error message

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: Iffffb8a5c9daf8f474dfc0237082ae96f06775fc
diff --git a/arthur-scripts/parse_refspec.py b/arthur-scripts/parse_refspec.py
index 963fc70..83fd30e 100755
--- a/arthur-scripts/parse_refspec.py
+++ b/arthur-scripts/parse_refspec.py
@@ -46,7 +46,7 @@
 changes.pop()
 
 if not changes:
-    raise Exception("resolved to nothing.")
+    raise Exception("Can not find anything.")
 
 if len(changes) > 1:
    print_topic_tip(changes)