Fix import line for setup.py

Build fails in case python-setuptools is not installed.

Change-Id: I1611f3560db82a4a48c51a9f614a813a9a540698
Signed-off-by: Peter Ginchev <pginchev@cisco.com>

vpp-api/python/setup.py

@@ -13,9 +13,9 @@
 # limitations under the License.
 
 try:
-    from setuptools import setup, command, Extension
+    from setuptools import setup, Extension
 except ImportError:
-    from distutils.core import setup
+    from distutils.core import setup, Extension
 
 setup (name = 'vpp_papi',
        version = '1.2',