setup.py: fix location of libev includes and libs

for some reason we missing that the path we carfully added
are not actually used

Author: fruch

setup.py

@@ -151,9 +151,9 @@ def __init__(self, ext):
 
 libev_ext = Extension('cassandra.io.libevwrapper',
                       sources=['cassandra/io/libevwrapper.c'],
-                      include_dirs=['/usr/include/libev', '/usr/local/include', '/opt/local/include'],
+                      include_dirs=libev_includes,
                       libraries=['ev'],
-                      library_dirs=['/usr/local/lib', '/opt/local/lib'])
+                      library_dirs=libev_libdirs)
 
 platform_unsupported_msg = \
 """