validate.py: emphasize pep8 unavailability

Change-Id: Ic709d47287a87dd287e792605ad15a724f9788d8
Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org>
diff --git a/validate.py b/validate.py
index 1e981b4..45f0d22 100755
--- a/validate.py
+++ b/validate.py
@@ -11,7 +11,7 @@
     import pep8
     run_pep8 = True
 except:
-    print("PEP8 is not available")
+    print("PEP8 is not available!")
 
 
 def print_stderr(message):