now ansible shows nice message about missing json instead of traceback

Signed-off-by: Brian Coca <briancoca+dev@gmail.com>

lib/ansible/module_common.py

@@ -51,11 +51,6 @@ BOOLEANS = BOOLEANS_TRUE + BOOLEANS_FALSE
 # of an ansible module. The source of this common code lives
 # in lib/ansible/module_common.py
 
-try:
-    import json
-except ImportError:
-    import simplejson as json
-import base64
 import os
 import re
 import shlex
@@ -72,6 +67,15 @@ import pwd
 import platform
 import errno
 
+try:
+    import json
+except ImportError:
+    try:
+        import simplejson as json
+    except ImportError:
+        sys.stderr.write('Error: ansible requires a json module, none found!')
+        sys.exit(1)
+
 HAVE_SELINUX=False
 try:
     import selinux