fix(test): making the httpd testcase pass

Fixed expected values to remove failures like:
```
======================================================================
FAIL: test_should_work_with_real_data (testhttpd.TestHttpdCollector)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/mock.py", line 1210, in patched
    return func(*args, **keywargs)
  File "/home/rtoma/git/github/rtoma/Diamond/src/collectors/httpd/test/testhttpd.py", line 146, in test_should_work_with_real_data
    self.assertPublishedMany(publish_mock, metrics)
  File "/home/rtoma/git/github/rtoma/Diamond/test.py", line 186, in assertPublishedMany
    self.assertPublished(mock, key, value, expected_value)
  File "/home/rtoma/git/github/rtoma/Diamond/test.py", line 177, in assertPublished
    msg=message)
AssertionError: BytesPerReq: actual '5418.550000', expected 5418
```