fixed config test for config.set_multivar

config files have different priorities and only the highest one gets evaluated for set_multivar

src/pygit2/index.c

@@ -84,7 +84,6 @@ Index_add(Index *self, PyObject *args)
 {
     int err;
     const char *path;
-    git_index_entry* entry;
 
     if (!PyArg_ParseTuple(args, "s", &path))
         return NULL;

test/test_config.py

@@ -151,7 +151,7 @@ class ConfigTest(utils.RepoTestCase):
         new_file.write("[this]\n\tthat = foobar\n\tthat = foobeer\n")
         new_file.close()
 
-        config.add_file(config_filename, 0)
+        config.add_file(config_filename, 5)
         self.assertTrue('this.that' in config)
         config.set_multivar('this.that', '^.*beer', 'fool')
         l = config.get_multivar('this.that', 'fool')